"newbie" question about door lock circuit

[Farrar]

I am studying the door lock circuit on our cars while at the same time looking up various electric locking schemes from older vehicles. I have found descriptions online of "3-wire positive," "4-wire reversal," and "5-wire alternating positive." Which one is ours? Looks from the circuit diagram like five wires, but I don't know what "reversal" or "positive" means. Pretty sure everything on our car switches ground. Anyway, I am just curious since there are folks on this board who have way more electrical knowledge than me.

Thanks!

Farrar

[dmc6960]

Are you asking about the sense circuit or the solenoid circuit? The sense circuit has two leads, one for lock and one for unlock. When one is grounded it triggers its action. The solenoids are each powered by 3 leads, two positives from the controller (lock or unlock), with a common ground.

[dmc6960]

And that solenoid ground goes to the door harness/chassis, not the lock controller.

[Chris4099]

It sounds like those devices are intended to directly power the solenoids. Considering how much power they take, that may not be a good idea unless they are designed for it. Instead, just about every remote control device should have a ground trigger. You connect those two wires directly to the lock/unlock trigger wires on our door lock controller. That tricks the lock module into thinking one of the doors was locked/unlocked, so it will then activate the solenoids.

What exactly are you looking to add? Otherwise we are kind of shooting blind here.

[stevedmc]

I usually tell newbies to disconnect the door lock module and consider it an upgrade.

[Chris4099]

Me too. But I also tell them they can either rebuild them to be reliable (I've rebuilt a few myself) or just replace them with one of the digital modules. It's then a very simple matter of adding keyless entry and having modern car convenience. I haven't used a door key in 7 years!

[Farrar]

The knowledge I seek is only for theoretical purposes... my car came with LockZilla but I got rid of it. I would like to add keyless entry. I wanted to know if there was an online reference for our type of door lock system before I go poking around with constant/momentary engage/disengage signals from a remote control. Does that make sense?

[Chris4099]

The lock module's basic setup is it would monitor the lock/unlock trigger wires. When one of them went from an open circuit to ground, it would provide about 1 second of 12v to the solenoids which would lock/unlock them. So there are two sides. One does the lock and the other does the unlock. Each solenoid would have two circuits as well. When you energized one side, it would lock. Energize the other it would unlock. But you had to make sure it would only be energized for about a second. This is where the old system had troubles as the relays inside would become stuck leaving the solenoids engaged until the battery died or the circuit breaker tripped.

If you want to just get rid of the lock module (do away with how one door would lock/unlock with the other) and just use keyless entry, you can do that. You just have to make sure the keyless entry system can pass enough current for the solenoids (or use your own relays instead) and will energize them long enough. If it energizes them too long, you'll shorten the life the solenoids and too short, the solenoids my not be able to fully lock/unlock the doors.

Since most aftermarket and modern cars use actuators, that's where you are probably seeing the 4/5 wire type systems. Due to the higher power requirements, I wouldn't use an actuator system unless it's rated for solenoids. Or better yet, get a lock module and then any cheap keyless entry system will do as it just needs to provide a ground trigger for lock/unlock (almost all of them should do that). To make a stock module safe, just replace the relays inside (Toby and John sell them). There should be plenty of people that have them after installing the newer digital units.

[Bitsyncmaster]

The switch on the door connects when the lock is manually started to move. When that switch contacts, it fires the solenoid driver for about 200 ms. on the lockzilla or about 1 second on the OEM unit. The solenoids have two coils with the two coils going to a common ground. So the controller applies 12 volts to one of the coils for that short time to fire it.

[Farrar]

Thanks for the info, guys! I was planning on using two relays. I believe I remember reading on the old DMCTalk that LockZilla solved the problem of the sticking solenoids, but not the battery-drain problem. Since a keyless entry system will have its own drain on the battery, I was not wanting to re-install LockZilla.

[David T]

If you have a Lockzilla I would use it. Just remember it won't fix burnt solenoids so if yours are burnt they must be replaced, rewound or upgraded to actuators. If you don't want to use the Lockzilla they are worth a lot to others who can't find one. If you are going to use the OEM door locking module at least cut a 10 Amp fuse (NOT a circuit breaker) into the big red wire. Keyless remote entry (not remote actuators to open the doors) is a great upgrade because it saves a lot of wear on the door lock cylinders.
David Teitelbaum

[Chris4099]

I believe I remember reading on the old DMCTalk that LockZilla solved the problem of the sticking solenoids, but not the battery-drain problem.

Yes, both the stock module and Lockzilla use about 13ma of standby current. If you can handle a soldering iron, follow these directions upgrade the controller:
http://www.dmcnews.com/Techsection/pdfs/lockmod91.pdf

I did this and it's been working great for 8 years now. I no longer disconnect the battery these days because I know I can go for weeks without draining the battery!

[Chris Burns]

Does unhooking the door lock module help out with the solenoid problem? I dont need power door locks anyway, just as long as the doors work I'm happy:tongue2:

[jawn101]

Does unhooking the door lock module help out with the solenoid problem? I dont need power door locks anyway, just as long as the doors work I'm happy:tongue2:

Yes, since the solenoids receive their power from the lock module - that'd fix it nicely :)

I have to say though (one man's opinion) that when I got the car, I thought the same thing; that I didn't need the power locks. But it pretty quickly wore thin having to reach over inside to unlock the other door for my wife. The car is very wide and that tunnel is very high. It gets old :)

FWIW, I got the DPNW actuators to replace the solenoids and am using the stock lock module with 0 issues.

[Farrar]

Keyless remote entry (not remote actuators to open the doors) is a great upgrade because it saves a lot of wear on the door lock cylinders.

I have early-style door locks and a two-key system, so this is the main reason I would like to install RKE.

My solenoids are in fine shape. I would like to replace them with linear actuators, but I do not think I have the skill at this time, so that project will wait.

[jawn101]

..I would like to replace them with linear actuators, but I do not think I have the skill at this time, so that project will wait.

There is literally 0 skill required for that job :) Get the kit from Toby and Misty and it takes not even a half hour total. Takes longer to remove the lower door panel than anything. Panel off, two screws out. Unplug the harness and remove the solenoid. Plug in the new harness, two screws in the actuator, and clamp their supplied rod extender to the lower lock rod. 5 minutes per side not including the panel R&R :)

Oh, and there's a plug and play relay harness that goes in the relay box. That also takes 5 minutes to install.

[Bitsyncmaster]

There is literally 0 skill required for that job :) Get the kit from Toby and Misty and it takes not even a half hour total. Takes longer to remove the lower door panel than anything. Panel off, two screws out. Unplug the harness and remove the solenoid. Plug in the new harness, two screws in the actuator, and clamp their supplied rod extender to the lower lock rod. 5 minutes per side not including the panel R&R :)

Oh, and there's a plug and play relay harness that goes in the relay box. That also takes 5 minutes to install.

+1

Real easy to install once you get the panels off. But using the stock unit you need to use the relay kit with the actuators.

[Farrar]

using the stock unit you need to use the relay kit with the actuators.

Does that mean that LockZilla wouldn't need the relay kit?

Here are diagrams of the three type of systems I have found. Granted, these diagrams assume RKE has already been installed. Nonetheless, which one most closely resembles the DeLorean setup? Judging from what I know about the circuit, I think it's the first one... but I've been wrong before.

http://images.the12volt.com/12voltimages/3wireposlocks.gif

http://images.the12volt.com/12voltimages/4wrp.gif

http://images.the12volt.com/12voltimages/5wap.gif

Thanks!

[jawn101]

I know DPNW sells 2 kits, one for the stock module (includes relays for an extra $10) and one for digital modules with no relays. I am not sure what category the LockZilla falls in but I know who you could ask :)

[Farrar]

I know DPNW sells 2 kits, one for the stock module (includes relays for an extra $10) and one for digital modules with no relays. I am not sure what category the LockZilla falls in but I know who you could ask :)

The digital module from Houston is definitely out of my price range. If I had that kind of coin to drop on saving my door lock cylinders, then wiring my own relays for a $45 RKE system would be moot.

I guess I should ask Toby, but I hate asking vendors questions about products I am not buying. I used to work in a music store, and the salesmen really disliked it when people would waste their time like that. :(

[Bitsyncmaster]

The Zilla unit would need the same relay kit as the OEM unit. You need the relays to reverse the polarity to the actuators. The new smart ECUs already have built in polarity relays.

[Farrar]

OK, I think I am beginning to understand. So the actuators require a + pulse, but the switches switch - ?

[Chris4099]

Here are diagrams of the three type of systems I have found. Granted, these diagrams assume RKE has already been installed. Nonetheless, which one most closely resembles the DeLorean setup? Judging from what I know about the circuit, I think it's the first one... but I've been wrong before.

http://images.the12volt.com/12voltimages/3wireposlocks.gif

Correct, the one above is the "correct" one. You'll still want to make sure you find out how long the alarm sends the ground trigger since that will directly translate into the time the solenoids engage. Note that in the above setup, the purple and blue wires are the heavy gauge wiring on the lock module harness. The fused red wire would be from the circuit breaker that the red wire on the lock module normally plugs into. Remember, you will only have electric locking/unlocking from the remote. If you get into the driver side and want to lock the passenger side, you still have to reach over or lock it via the keyless entry (could be a problem if it has an alarm feature).

Finally, to make them compatible with actuators for a future upgrade, make sure to ground pins 87a on the relays. You can then buy Toby's kit and just swap them straight in (again the length of time they are energized is unknown and could be an issue).

[Bitsyncmaster]

OK, I think I am beginning to understand. So the actuators require a + pulse, but the switches switch - ?

The actuators need a + pulse and - pulse (reversed power and ground) to open and close.

The solenoids just require a + pulse on one coil to open or a + pulse on the other coil to close.

When I tried my lockzilla with actuators, one of the doors would not always unlock. I had to increase the pulse time to make it work. I have since designed my own ECU.

[Farrar]

I have since designed my own ECU.

I have just slogged through two weeks of logic, so I am not yet able to do anything like that. Only very simple circuits! :(

So if the actuators require a + pulse to open and a - pulse to close, that's a great starting point. Thanks! Looks like I have lots of homework to do. :)

[Chris4099]

So if the actuators require a + pulse to open and a - pulse to close, that's a great starting point. Thanks! Looks like I have lots of homework to do. :)

Actuators work like the window motors. Two wires only. Have the polarity in one direction, they lock. Reverse the polarity, they unlock. The solenoids have 3 wires, two positive (one for each direction) and a common ground. So when you convert to actuators, you don't use the common ground, but instead ground both wires and only energize one when you need to lock or unlock. That's why I say to ground pin 87a so your system effectively will work with either solenoids or actuators. It's basically what the digital lock modules do (but not the Lockzilla or stock module).

[Farrar]

So it sounds like when I upgrade from solenoids to actuators I will have an unused wire running from the relay compartment into the door. I guess since it will be disconnected at both ends it will not be a safety concern, but it sounds like it will be a bit messy.

[Chris4099]

The solenoid ground goes on to be part of the rest of the ground wires from the door. So it's not seen at the lock module harness. You technically don't need it as the solenoid just grounds to the door frame which is why if you get a door launcher kit, you can use re-purpose that to trigger the launcher actuator. So at this stage, I wouldn't worry about it and just leave it unused once you upgrade to actuators.

[Farrar]

One question: since the door switches are dual-throw rocker switches, don't they send a constant signal instead of a pulse? I assume the door lock module contains some sort of "constant to momentary" converter circuitry, correct? Is this partly what causes the high standby current?

[Chris4099]

Correct, the wiper switches keep it grounded. The lock modules only briefly power the solenoids when the trigger wires go from open circuit to ground. Nothing else happens if the signal stays grounded or goes back to an open circuit state. The high standby has to do with the older transistors according to the PDF that Elvis wrote. Replace them with modern ones per the directions (along with a few resisters), you can bring the standby current way down. Don't forget the Lockzilla is the exact same setup (just improved relays and a circuit breaker). So if you don't like it's high standby current, you can perform the same fix per the PDF.

[Bitsyncmaster]

Correct, the wiper switches keep it grounded. The lock modules only briefly power the solenoids when the trigger wires go from open circuit to ground. Nothing else happens if the signal stays grounded or goes back to an open circuit state. The high standby has to do with the older transistors according to the PDF that Elvis wrote. Replace them with modern ones per the directions (along with a few resisters), you can bring the standby current way down. Don't forget the Lockzilla is the exact same setup (just improved relays and a circuit breaker). So if you don't like it's high standby current, you can perform the same fix per the PDF.

The lockzilla circuit is a little different but basicaly the same poor design as the OEM unit. Both use a large capacitor to hold the relay closed for the pusle. This causes the relay contacts to open to slowly and burn the contacts, hence they may get stuck holding power on the solenoids.

Both also use a 1.0 Kohm pull up resistor on the switch inputs. So that is the major load that always drains the battery. With the "Elvis" modification, you use higher gain transistors and change that pullup resistor to 10 K ohms and reduce the load 10 fold.

[Farrar]

It looks to me like the reason they needed the lock module is because the rocker switches in the doors create a constant-contact situation. If that situation were eliminated, would there be any need for a lock module? In my head the rest could be accomplished with a pushbutton switch and a couple of relays. I must be missing something, right?

[Chris4099]

You would need to be careful if you have them manually switched. The nice part of the lock module is it would be a timed pulse to the solenoids each and every time. If say you have a switch in the passenger compartment and something accidentally presses and holds it, you'll burn out your solenoids and/or drain the battery. Also if they are pressed too fast, the solenoids won't be engaged long enough to fully lock/unlock the doors (probably more of an issue if actuators are used instead of solenoids).

[Farrar]

if they are pressed too fast, the solenoids won't be engaged long enough to fully lock/unlock the doors

This explains a problem I have had with electric locks in previous cars of mine. I always assumed it was because I hadn't pressed the switch down far enough even though I had heard it click. Now I realize that the actuators hadn't received a long-enough pulse! Fascinating!

[Chris4099]

There can be several causes to that issue. I've had actuators go bad and were no longer strong enough or have a long enough stroke to work the locks. Could also be a mechanical issue where there's too much resistance for the actuator to overcome. That's why whenever somebody is troubleshooting their locking system, I always tell them to disconnect the lock module and make sure everything mechanical is working perfectly. Trying to troubleshoot the electrical part with a unadjusted or broken locks is next to impossible!

[Bitsyncmaster]

Yes you could just use four push button switches without the need for a controller or the door switches. You just need to be sure they don't accidentally get pushed for to long. It would probably be safe up to 5 seconds.

[Farrar]

How about something like this?

8916

The pink and red wires will be sending about a half-second pulse to the actuators, so the RKE signal could be patched into those wires (with protective diodes).

Or would I need separate capacitors and resistors for each relay? I was just trying to keep things simple, but remember I'm new at this and self-taught...

Thanks!

[Bitsyncmaster]

How about something like this?

8916

The pink and red wires will be sending about a half-second pulse to the actuators, so the RKE signal could be patched into those wires (with protective diodes).

Or would I need separate capacitors and resistors for each relay? I was just trying to keep things simple, but remember I'm new at this and self-taught...

Thanks!

1) Always use pin 85 for the coil ground side. Some relays have suppressors (diodes) and powering the coil backwards would blow the suppressor.

2) You would need a larger capacitor to get near a half second. About 500 uf.

3) Your copying the fault of the OEM controller. Opening the relay slowly would burn the contacts and cause it to stick.

4) The actuator needs a ground on the lead not powered by 12 volts.

[Farrar]

Thanks, Dave! I feel like I am learning something. :)


1) Always use pin 85 for the coil ground side. Some relays have suppressors (diodes) and powering the coil backwards would blow the suppressor.

Ah ha, I was under the impression that the coil was not polarity-sensitive. Thanks for clearing that up! So the diodes I have between pins 85 and 86 would not work? Should I buy a relay with built-in diodes? I didn't know those existed!


2) You would need a larger capacitor to get near a half second. About 500 uf.

Man, I am bad at math. Thanks. I will run it through my little circuit simulation program. Unfortunately, the program doesn't have an amperage setting.


3) Your copying the fault of the OEM controller. Opening the relay slowly would burn the contacts and cause it to stick.

OK, so now I am learning about the original controller. Cool! :) What would cause the relay to open too slowly? Low battery voltage?


4) The actuator needs a ground on the lead not powered by 12 volts.

This confuses me -- someone said that I should ground pins 87a of the relays that send the pulse to the actuators. The actuators themselves will be grounded to the door panel. Does that mean that those 87a grounds are redundant?

Thanks again!

[David T]

One trick in getting a relay with a lot higher rating is to use a DPST relay and use both sets of contacts in parallel to double the rating. You need a capacitor to reduce the arc when the contacts open. You want as short a pulse as reliable to keep from burning up the solenoids. Solenoids with shorted windings will not pull as strong and will consume more current then necessary. You should include a manual resetting breaker or a fuse just in case a relay gets stuck or you operate the solenoids too often in too short a time.
David Teitelbaum

[Farrar]

David T, I am planning on putting together this circuit when I upgrade to actuators. Would you still recommend the above for those instead of solenoid application?

Thanks!

[Chris4099]

This confuses me -- someone said that I should ground pins 87a of the relays that send the pulse to the actuators. The actuators themselves will be grounded to the door panel. Does that mean that those 87a grounds are redundant

I suggested that because this keeps both leads to the actuator grounded. Power one side and it lets the current flow in one direction through the actuator. Power the other side and the direction reverses and lets the actuator go in the other direction. You do not ground the actuator to the door (remember it's two wires, not 3 like the solenoids).

[Farrar]

I suggested that because this keeps both leads to the actuator grounded. Power one side and it lets the current flow in one direction through the actuator. Power the other side and the direction reverses and lets the actuator go in the other direction. You do not ground the actuator to the door (remember it's two wires, not 3 like the solenoids).

So I think I begin to understand this now: you want the actuator to "rest" at ground instead of having no connection when it is not being used? And this (grounding 87a) is to prevent it from moving accidentally?

[Chris4099]

Nope, the actuator works just like the window motor. Two wires and will go in one direction based on the polarity of the circuit. Reverse the polarity and the actuator goes in another direction. In order to do this using two SPDT relays, you have to have both leads grounded. That way when one relay is switched from ground to 12v, the other one is still grounded and lets the actuator run. Once switched off, the relay grounds that end and the other end can be switched on to reverse the direction.

[David T]

Actuators use a lot less power than solenoids. You do not have to take as many precautions with them as you do with solenoids. They are also lighter and you may be able to release the torsion bars 1 spline so the doors won't bounce hard when they open. You will need to keep power on them a little longer than solenoids so they may require a longer "on" time to lock or unlock.
David Teitelbaum

[Bitsyncmaster]

ISO Relay

Contact arrangement for the ISO and Super ISO relays
The ISO relay has rather oddly numbered contacts, the system having been carried-over from the original German DIN specification. Each contact is 6.35 mm (1/8") wide and 11 mm (7/16") long.

Note that, while it is electrically irrelevant which way round the coil is connected, it is usual to make contact 85 electrically closest to ground (see Using Relays). Keeping to this convention helps others who may in future have to diagnose any problems.

Where a bracket is fitted, there appears to be no convention as to its position. I have seen examples with the bracket closest to contact 87, 85 and 30. In many US GM vehicles, the relays are in a bank, high on the bulkhead. They are retained on a common bracket that has a number of tongues each of which can fit into a slot, located on a relay. That slot is closest to contact 30 and some relays with individual metal brackets are GM type relays, the slot being used as the bracket retainer.

Always mount relays with the contacts pointing down, this attitude prevents water build-up between contacts.

Contact
Number
Function

85
Coil Low

86
Coil High

87
NO contact

87A
NC contact

30*
Common

* Contact 30 is sometimes marked 30/51.

[Farrar]

Thanks, Dave.

Getting back to this:


3) Your copying the fault of the OEM controller. Opening the relay slowly would burn the contacts and cause it to stick.

What would cause the relay to open too slowly?

[Bitsyncmaster]

Thanks, Dave.

Getting back to this:



What would cause the relay to open too slowly?

When you press the button, the cap is discharged so you get a quick operation of closing the relay. Then as the cap charges the relay current slowly drops until the current is to low to keep the relay closed. So the relay spring slowly pulls the relay open.

The correct way to do it....have a timing circuit that drives the relay coil fully on and fully off. You would need a transistor or MOSFET to drive the relay.

[Farrar]

You would need a transistor or MOSFET to drive the relay.

And with this I am definitely out of my depth. :lol: I haven't studied transistors yet.

Thanks!

[David T]

The capacitor is meant to go across the load contacts, not the relay coil circuit. It suppresses the arc to prevent the contacts from arcing and welding themselves together. This happens because of the large inductive load of the 2 large solenoids and the DC current. You can do that and/or use much larger capacity relay contacts.
David Teitelbaum

[Farrar]

This happens because of the large inductive load of the 2 large solenoids

You mean actuators?


The capacitor is meant to go across the load contacts, not the relay coil circuit.

I put a diode over the relay coil's terminals, not a capacitor. The program I am using is not meant for drawing schematics, so I do the best I can with approximations of the symbols I know. Sorry.

[Farrar]

All right, I've done some reading and I am practicing my soldering, but I don't think I will be able to open LockZilla without destroying the case.

Nonetheless --

It looks like the "lock doors" light should come on even with the module removed, since it is grounded through the SPDT lock switch. Mine does not do this, and I have verified its bulb (actually, an LED replacement) works. It looks like I have a problem elsewhere.

For other reasons, the interior of my car has largely been removed -- carpet, seats, console, shelf panel, etc. -- has been removed. The kneepads and dash are still in, but most of the wiring on the inside is visible. It looks like I have some exploration to do...

BTW, I found a Remote Keyless Entry module on sale for $34. I might splurge on it as a test. It has its own internal relays, like the stock module, but also built-in fuse protection. The pulse is variable between 0.7 seconds and 3.5 seconds. However, I will have to reconcile the wiring diagrams (such as they are), since our type of locking mechanism is not listed: they have only "reverse polarity," "one-wire negative," and "one-wire positive." More stuff for me to learn! :D

[Chris4099]

I suspect "reverse polarity" is the one you want for actuators. And if it already has relays, then you are pretty much set. Just wire in the 4 heavy gauge wires that used to go to the lock module directly to the controller and then install the actuators. Adjust the pulse to about .5 seconds and you should be set! If you want to have a push button to lock the doors once you are inside (without having to press the remote), then you'll probably want to go back to your relay setup and use the "one-wire positive" assuming that uses 2 positive triggers (one for lock, the other unlock).

You are correct about the "lock door" light not needing the lock module. See if you are getting 12V to it when the ignition is on. If not, then you need to check that side of the circuit. If you do, then it's probably the ground side. To test that, have at least one door unlocked. Verify that the bulb is now grounded. It should go to ungrounded once both doors are locked.

[Farrar]

I used this circuit simulator java applet (http://www.falstad.com/circuit/) to make some sort of extremely vague approximation of the DeLorean's door lock circuit, which any electrical engineer would probably find uproariously funny, but which I found to be useful and instructive. I see what y'all are talking about -- a 1000 uF capacitor takes over 15 seconds to discharge! However, the standby current with 10k resistors in place is only 1.21 mA.

I will see if I can Dremel my way into LockZilla and buy the necessary upgrade components at RadioShack. I am still nervous about my soldering skills -- I would hate to ruin LockZilla through my clumsiness. Although it wouldn't be the first time I destroyed something in order to learn, the unit is no longer available, and if it breaks there's no sending it off to be fixed!

The RKE system I bought comes with a starter disable "module" (actually a relay which connects to the control unit). I am not sure I am interested in it since I already have a "start inhibit relay." :lol: Nonetheless, this looks pretty straightforward. The trick will be making sure that the switch inside the car still works once I am inside, so that I don't have to use the remote control to lock the doors while I am in the car.

For what it's worth, here's a link to the installation manual (http://www.bulldogsecurity.com/manualsnew/KE1702%20%20ManualLOW.pdf). I'm not sure if anyone's interested in what I come up with at this point, but I will post it anyway just for reference.

[Farrar]

OK, so I opened up the door lock module and it does not look like what I expected from Elvis' rebuild instructions:

- The capacitors are different
- The relays look different
- The diode at the top (just behind the right-side capacitor) has been removed
- The two diodes in the middle have been replaced with something else (resistors? smaller diodes?)

9070

The backside is different, too: two new things have been soldered on.

9073

They are labelled thus:

104K
400B
...

I don't know what to do about these so I will leave them in place.

I have some 10k resistors at hand so I am going to replace those. I will not mess with anything else. Then I will patch in the Remote Keyless Entry and see what happens.

[Chris4099]

It probably won't work unless you replace the transistors too. You can ask Elvis but I would assume its safe to just leave the rest of the stuff there.

[jawn101]

It probably won't work unless you replace the transistors too. You can ask Elvis but I would assume its safe to just leave the rest of the stuff there.

Actually, if Elvis is reading this - or anyone else who's done his mod - do you have part numbers or any info on where to get the relays? Obviously the Darlington transistors and capacitors are pretty simple, but from his doc:

"The most important thing is to get new relays and to replace them!
They and only they are responsible for your burned solenoids ! I know where to find
these relays in germany, but I can‘t tell you where you can get them in the US."

So, who does know? :)

[Chris4099]

The Lockzilla ones should be better then stock ones, but don't quote me on that. Toby carries replacement relays and are nice in that they are sealed so they would be an upgrade over the ones you have now.

http://www.delorean-parts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=DPNW&Product_Code=101421-RS&Category_Code=

[Bitsyncmaster]

OK, so I opened up the door lock module and it does not look like what I expected from Elvis' rebuild instructions:

- The capacitors are different
- The relays look different
- The diode at the top (just behind the right-side capacitor) has been removed
- The two diodes in the middle have been replaced with something else (resistors? smaller diodes?)

9070

The backside is different, too: two new things have been soldered on.

9073

They are labelled thus:

104K
400B
...

I don't know what to do about these so I will leave them in place.

I have some 10k resistors at hand so I am going to replace those. I will not mess with anything else. Then I will patch in the Remote Keyless Entry and see what happens.

Your photos do not look like a lockzilla unit. Mine is compleatly different. It has sealed 70 amp relays on mine and the PCB is different.

[Farrar]

Your photos do not look like a lockzilla unit.

Oh, I forgot to mention that this is not a LockZilla unit. This is an old stock unit, or it was supposed to be. The previous owner included it in a box of parts that came with the car. LockZilla is still on the shelf. I have not been able to open the case.

Sorry for the confusion!

[Chris4099]

Oh, I didn't know you still had the stock module. In that case, just replace the relays, transistors and resistors. You now have a "better than Lockzilla" unit. You can use that and just sell the Lockzilla at that point.

[Farrar]

You can ... sell the Lockzilla ...

Well, not really. When trying to open the case, my Dremel tool instead of cutting the plastic just ended up melting it. Then my hand slipped and I ended up cutting the harness. The unit might be salvageable, but it is certainly not usable in its current state.

The relays and capacitors certainly look newer than 1981 to me. I will try to replace the resistors and transistors. No time for that until Thursday, though.

[jawn101]

So this thread prompted me to start working on my own lock module.... does anyone know the exact specs of the resistors used in the Elvis lock mod document? The pictures are a little too blurry to read the color code accurately. He said 10kohm but not the tolerance or if any particular material was preferred, etc.

Anyone have a good source for the BD679 transistors? Radio Shack doesn't seem to have them (their selection has gone way downhill in the last 20 years)

Also, when I removed my module, I heard something rattling around inside. Opened the case and turns out that D4 (the diode just above the wiring bundle on the capacitor side) had broken off and there are just leads running nowhere. What kind of diode is that?

On the plus side, the relays look to be in very nice shape. Odd thing is that this module works fine. What's that D4 diode even do?

[Bitsyncmaster]

The 10 K ohm can be any type and any accuracy. 1/4 or 1/8 watt will be fine.

[jawn101]

The 10 K ohm can be any type and any accuracy. 1/4 or 1/8 watt will be fine.

Great, thanks Dave. Any clue on that broken diode? :) I see that it goes to the violet +12v wire, which means that portion of the circuit has been dead for who knows how long. How come it kept working? What's that line for?

[Bitsyncmaster]

Great, thanks Dave. Any clue on that broken diode? :) I see that it goes to the violet +12v wire, which means that portion of the circuit has been dead for who knows how long. How come it kept working? What's that line for?

I don't the schematic handy but I bet that diode is just to clamp the spikes when the relays switch off.

[jawn101]

OK, so I opened up the door lock module and it does not look like what I expected from Elvis' rebuild instructions:

- The capacitors are different
- The relays look different
- The diode at the top (just behind the right-side capacitor) has been removed


Farrar, isn't it funny - check out my pics in the post a couple up. My capacitors are also the more modern style and my diode D4 is also gone. But it was rolling around inside the case - looks like it just broke off the leads. Could that be what happened to yours too? It looks like there's potential for the wire harness to put a lot of pressure on that diode and maybe it just wore out over time.

[Farrar]

check out my pics in the post a couple up.

I did. Do you have a fused resistor soldered to the back of yours? It looks like mine does. Seems to be some sort of protection.

I believe that before LockZilla, Grady used to rebuild and upgrade the lock modules. Mine may be one of those rebuilt/upgraded ones.

[jawn101]

I did. Do you have a fused resistor soldered to the back of yours? It looks like mine does. Seems to be some sort of protection.

I believe that before LockZilla, Grady used to rebuild and upgrade the lock modules. Mine may be one of those rebuilt/upgraded ones.

Nope, nothing on the back.

Having a hell of a time finding the right Darlingtons and diodes for this thing. Where'd you get yours?

[Bitsyncmaster]

Nope, nothing on the back.

Having a hell of a time finding the right Darlingtons and diodes for this thing. Where'd you get yours?

http://search.digikey.com/us/en/products/BD681S/BD681S-ND/976567

[jawn101]

http://search.digikey.com/us/en/products/BD681S/BD681S-ND/976567

Oh, great Dave - thanks. I was looking at those 1N4003 diodes too and realized they aren't a Zener design like the BZV85C18 were. Does that matter in this circuit?

[Farrar]

Having a hell of a time finding the right Darlingtons and diodes for this thing. Where'd you get yours?

I consulted an electronics-savvy friend of mine who looked at the board and said the transistors didn't need to be replaced. I got my parts at RadioShack. To my knowledge, ordinary rectifier diodes will do the job.

[Bitsyncmaster]

Oh, great Dave - thanks. I was looking at those 1N4003 diodes too and realized they aren't a Zener design like the BZV85C18 were. Does that matter in this circuit?

Use the 1N4006 for all six black doides. The two glass diodes are 1N4148 signal type diodes. I don't see any zeners.

[Bitsyncmaster]

I consulted an electronics-savvy friend of mine who looked at the board and said the transistors didn't need to be replaced. I got my parts at RadioShack. To my knowledge, ordinary rectifier diodes will do the job.

If your doing 10 Kohm resistor changes, you will need the higher gain transistors.

[Farrar]

If your doing 10 Kohm resistor changes, you will need the higher gain transistors.

Wow, that's good to know. Thanks, Dave!

[jawn101]

Use the 1N4006 for all six black doides. The two glass diodes are 1N4148 signal type diodes. I don't see any zeners.

Wacky. The one that broke off my board (D4 on the schematic) is clearly labeled as a BZV85C18, which the data sheet says is a Zener. But I'm not sure I see the need for the backfed current in what we're assuming to be a spike suppressor so I'm with you.

[Bitsyncmaster]

Wacky. The one that broke off my board (D4 on the schematic) is clearly labeled as a BZV85C18, which the data sheet says is a Zener. But I'm not sure I see the need for the backfed current in what we're assuming to be a spike suppressor so I'm with you.

D4 probably was a zener but there is no resistor to limit the current. So if the input voltage (12 volts) exceeded the zener voltage it would blow the zener. I would not install D4 but if you must use a 20 volt zener.

[jawn101]

D4 probably was a zener but there is no resistor to limit the current. So if the input voltage (12 volts) exceeded the zener voltage it would blow the zener. I would not install D4 but if you must use a 20 volt zener.

Maybe that's why it was gone (removed?) on both mine and Farrar's units. Do you think we should bridge the gap where it was with a jumper or just leave it open?

[Bitsyncmaster]

Maybe that's why it was gone (removed?) on both mine and Farrar's units. Do you think we should bridge the gap where it was with a jumper or just leave it open?

It must be left open. If you jumpered it, you would short circuit the 12 volts.