DeLorean Ground Schematic

[content22207]

I am starting to map out all of the ground wires on a DeLorean (the major ones at least), and I've already made an interesting discovery: each set of headlights (and its associated side and front lights) is grounded directly to the bulkhead bolt. These are the seven 12 gauge wires on the bulkhead bolt:
- Left headlight (and side/marker lights)
- Right headlight (and side/marker lights)
- Ground junction behind A/C duct
- Ground junction behind glove box
- Ground junction under console (passenger side, towards rear)
- Ground junction in relay compartment
- Ground junction behind bulkhead connectors

The bundle of wires that everyone gets so excited about on the radio bracket are nothing more than two bit players in the scheme of things.
- Individual panel bulb
- Individual panel bulb
- Individual panel bulb
- Individual panel bulb
- Radio
- Line out
Conventional wisdom that you can correct much of anything by running a large gauge wire from the radio bracket to the body bolt directly below it is total nonsense (unless you've got a big honking radio).

Two of the bigger trouble spots for owners (fuel pump/inertia switch and instrument cluster) are *NOT* grounded to the radio bracket. They come together in the junction behind the A/C duct, then one 12 gauge wire takes them (and a few other things) to the back of the car.

I'll add updates as more & more of #2508's wiring harness is torn apart....

Bill Robertson
#5939

Hold the line on that glove box junction. There is definitely a large gauge wire from the bulkhead bolt to that general area of the car, but there's an identical gauge wire coming off the blower motor -- I need to unwrap everything and see if the blower motor passes through a junction or if it's grounded directly.

Bill Robertson
#5939

[dn010]

This is crazy...so they'd rather run wires back and forth the length of the car to ground things instead of just have a main ground? If it was concerns over cost which prevented them from doing this, I don't see how it would have been cheaper to run all these lengths of wire, cut them, solder them, crimp them, cover them.... they should have just incorporated a separate line in the harnesses [which is obviously what we are doing now] which would have taken less room then dozens single black ground wires that are there now...

By the way, thanks Bill for posting, I'm sure it is taking a lot of detective work and time which you don't even need to do. This is helpful, at least to me it is. Instead of running some select grounds all over the car, I believe I may cut a few grounds (like the headlights) and just route them to the ground bus in their area. Thanks again.

[dn010]

From this discussion, it would be simple to create a diagram. Only thing is that there may be more that have not been discovered yet.

[content22207]

Wouldn't it be great to have a harness diagram showing every wire junction location. I guess this was never a document released from DMC.

I'm working on it:
4422

Bill Robertson
#5939

Apparently #2508 has donated its body to science (I am slowly unwrapping its entire wiring harness).

This is what I've got so far:
4423

Note the question marks on the last two grounds from the front junction. I'm pretty sure one of them is the windshield wiper motor, but I can't find the damn thing to verify that -- does anybody know where it is? I suspect the other small gauge wire goes to the turn signal/windshield wiper delay chassis, but haven't unwrapped enough to verify that yet.

I'm taking a DeLorean break (these little cars *DO* burn you out), then I will trace down the large gauge wire that passes in front of the glove box. I suspect it's the blower motor.

There are only 5 large gauge wires in the console harnesses before the rearmost junction on the driver's side, all of which appears to come from the ECU compartment. I'll know more after the break.

Bill Robertson
#5939

I'll trace the last few wires tomorrow:
4430

Bill Robertson
#5939

These are my ground buses (with the future addition as a dotted line) laid over a working copy of the factory ground schematic:
4436
Remember that, except for the headlight extension, my bus is significantly larger gauge than even the factory large gauge wires (4 versus 12).

I now know that making the stainless bar behind the headlights into a ground block was a bit redundant, but it does eliminate the possibility of problems at the washer bottle connector. I may move #2508's trunk light to it for that very reason (#5939's front end is buttoned up, and it's going to stay buttoned up).

My fuel pumps are grounded directly to the frame.

Bill Robertson
#5939

[dn010]

While I do have the continuous length of uncut wire running from bulkhead to the radiator/frame ground - with no breaks or attaching points between the 2 locations (I just didn't think I'd need these in the future) - I didn't opt to ground it to the frame on the bulkhead side. My ground bus runs to the bulkhead junction, from there are 2 more 4 gauge wires - one to the battery and then one to the engine. From the battery, the battery wire runs to the frame so I didn't see a need to ground to it twice.

[Bitsyncmaster]

Good work Bill. If that other ground common to the dash ground is the blower then I will do another frame ground for that.

[dn010]

Bill, can you tell me exactly where the cluster containing inertia switch ground is located behind ac duct? What do I need to take off to see this? I had a hell of a time with the radiator support, the bolt was pretty rusted.so I lost a lot of time getting that removed so I could affix the front of my bus. everything else is all connected for the most part.

[content22207]

The bundle of wires that everyone gets so excited about on the radio bracket are nothing more than two bit players in the scheme of things.
- Individual panel bulb
- Individual panel bulb
- Individual panel bulb
- Individual panel bulb
- Radio
- Line out
Conventional wisdom that you can correct much of anything by running a large gauge wire from the radio bracket to the body bolt directly below it is total nonsense (unless you've got a big honking radio).

Correction: the bundle of wires that everyone gets so excited about on the radio bracket are nothing more than a couple of capacitors, and of course the radio itself.

Individual A/C panel bulb grounds are connected at a junction about an inch or so aft of the radio bracket.

Bill Robertson
#5939

[content22207]

Bill, can you tell me exactly where the cluster containing inertia switch ground is located behind ac duct? What do I need to take off to see this?

Start at the door diodes, then follow the big bundle of wires going up into the dash with your hand and you should feel it.

If you want to use that junction as your grounding point you will probably need to take the seat out so you can lay down with your head under the dash. I was able to manipulate individual wires in the junction to count them, so on #2508 at least it won't be too bad (#2508's steering column is currently out of the car -- don't know if that makes a difference).

The biggest problems seem to be the inertia switch (not a problem for me because my pump is grounded to the frame) and the instrument cluster (lots of owners report gauge problems). I suppose you could simply tap those devices into your bus closer to the source rather than at the junction.

I am going to use the junction simply because it's a cleaner installation. I will use 4 gauge battery cable and a copper lug to be consistent with the rest of the bus.

Bill Robertson
#5939

[dn010]

No wonder I couldn't find it, i was looking on the wrong damn side of the car. Now that I've located it, I'll have to plan a way to ground this to my bus, looks like its going to be a pita but doable. I seem to notice that when I turn things on (car off) I am having much less voltage drops. Especially the headlights and blower, those together used to make the needle sink like a stone, now it barely moves. I cannot compare voltage at the battery since I never measured prior to this work which I wish I had. Ill have the car running either tomorrow or friday to see what my charging voltage and pump voltage is.

[WelmoedJ]

Bill,

There's a ground wire behind the panel that covers the fuel fill hoses.
The wire is attached to a bolt that runs through the "firewall" and connects to the pedal box.
I have traced this wire to be the ground for the fuel sender.

Welmoed.

[Bitsyncmaster]

Yes it's just the dash volt gauge that sees that ground offset caused by the fuel pump current (and now maybe the blower current) that makes it read lower. What your doing with the large ground buss should fix it. But my plan is just to make those two large current grounds move to the frame. Then the original ground wire only has to conduct the light ground currents and hence not offset the dash gauge.

I have already put the inertia switch ground to it's own frame ground. Now I will move the blower ground to it's own frame ground. I would do the same, run a 10 AWG wire to the shifter mount bolt. This should increase the blower motor voltage a little also.

edit:

Actually all the dash gauges are seeing the offset but it seems the most affected gauge is the volt gauge.

[nofear365]

If it helps I have my video of the wire harness breakdown here:


http://youtu.be/_IND69PZ6C4

http://www.youtube.com/watch?v=_IND69PZ6C4

[content22207]

While poking around under #5939's dash I realized a few errors from the front junction. This is a corrected copy:
4469

I still hope to trace out the relay compartment grounds later today.

Bill Robertson
#5939

[Bitsyncmaster]

While poking around under #5939's dash I realized a few errors from the front junction. This is a corrected copy:
4469

I still hope to trace out the relay compartment grounds later today.

Bill Robertson
#5939

So the headlights go back to the harness ground? Wonder why they did not use the frame ground like the fans.

[content22207]

The headlights (and side/front marker lights) go directly to the bulkhead bolt, thence to the frame.

Bill Robertson
#5939

[dmc6960]

Great work Bill. A suggestion if I may...

Put a pass-through of the inertia switch with perhaps a dashed line leading through the washer bottle connectors to the fuel pump. Its an important enough circuit I feel the complete path should be mapped.

[content22207]

Purple/Black is a switched ground. It's no different in principle than Purple/White. This schematic shows black wires only. Any wire you ring out on this schematic should beep to the negative battery terminal.

Bill Robertson
#5939

[content22207]

As a world renown Nazarene once said, it is finished:
4482

Actually I have labeled this file "Final1" because there are still at least three unknowns/assumptions subject to change:

1) The large gauge wire from the junction behind the A/C central duct is assumed to be the the windshield wiper motor -- until I figure out where the damn thing is and can visually verify it, that is subject to change. The second large gauge most likely is the inertia switch because it has the same gauge wire attached. The third large gauge wire was verified all the way back to the bulkhead bolt by unwrapping the harness. I unfortunately can not unwrap the harness forward to trace the other two large gauge wires because it disappears between a metal superstructure and the dash.

2) The small gauge wire to the wiper delay module continue somewhere (annoying door buzzer perhaps?). I do not have annoying door buzzers in either of my cars, so I can't verify that.

3) The small gauge wire that disappears by the windshield is assumed to be the wire that emerges from underneath the windshield trim and is attached to the fender -- I haven't pulled the trim off yet to verify.

All other wires were visually verified by unwrapping the harness and following them to see where they go. I am now the proud possessor of a DeLorean with no front suspension (or condensor/radiator/fans), no fuel delivery system, no interior, *AND* a whole lot of loose wires. Anybody want to come over with a couple rolls of electrical tape and help me put this thing back together?

So there you have it. The next time someone laments that they have no idea where something is grounded on these stupid little cars, just point them to this thread.

Bill Robertson
#5939

[content22207]

Well that didn't last long....

First revision:
- Redraw glove box switch and passenger door plunger to more clearly represent that the wires are ganged
- Change "Useless Bolt" to "Dashboard Bolt" (I was hot, tired, and irritable when I wrote that)
- Add sidelights to the *ONE* 16 gauge ground wire from the back of the car (what was Lotus thinking?)

4484

Bill Robertson
#5939

DMCTalk is automatically downsizing my original (1300 x 1600 pixels). If you want a larger copy, shoot me your eMail address.

Bill Robertson
#5939

[Delorean02378]

Raffle Tickets Anyone?

And this part of the wiring harness is to wrap around the lady's neck who interrupted my video and strangle her!



Kirk

[content22207]

The two black wires from the Lambda ECU to the bulkhead connectors were ID'd using Dave Delman's bulkhead connector diagram. Unfortunately his diagram does not correspond well to the DMC factory wiring diagram. The wiring diagram does indeed show three ground wires coming off the Lambda ECU:
- One grounds the case (the screw on top of the harness connector)
- One grounds Pin 5
- One grounds Pin 16

Tomorrow I will trace exactly which two of the above go to the bulkhead connectors, and relabel my schematic using connector color and position only (I'll use Dave's numbers). Dave does have the wires in the correct places, but I find it hard to believe that the control pressure regulator is grounded through the Lambda ECU rather than its housing.

The four bulkhead ground wires coming off the bulkhead junction were also ID'd using Dave's diagram (notice he's left the Yellow connector blank). He does have the rear lighting ground correct, but I'm at a total loss if the auto trans connectors are ID'd properly. They're in the right positions -- I just don't know for sure what they're grounding in the trans.

Bill Robertson
#5939

[Bitsyncmaster]

So the blower and the head lights have there own ground wire running back to the bulkhead. So those should not affect the dash volt gauge.

So in my opinion the only real dumb thing they did was connect the inertia switch ground common to the dash ground. I still think they should have connected the front lights to the frame ground and that would have saved them wire and running through the connector pins. I may make those front lights a frame ground when I pull those front connectors to install new pins.

What size wire ties that bulkhead common to the frame?

[sean]

DMCTalk is automatically downsizing my original (1300 x 1600 pixels). If you want a larger copy, shoot me your eMail address.

Bill Robertson
#5939

email me the original and I'll get the larger version posted.

[content22207]

Gotta make a few changes first:

The lambda harness connector in the car doesn't match the wiring diagram at all. The wiring diagram shows 9 pins. The connector in the car has 34 positions, but only 8 pins. Black wires in the car are also in different positions than the wiring diagram. I guess DMC made an 11th hour ECU change but never updated the wiring diagram. I have labeled my schematic "Far End" and pointed with an arrow. The two black wires are at the far end, adjacent to each other.

I have no idea what these wires do. All my K-Jet wiring is ripped out, so I can't ring them out to whatever used to be on the far end of the bulkhead connectors. To be brutally honest, I don't know for certain that they are even ground wires. They are black. They are in their own little worlds (they are not connected to chassis ground without something at the far end doing so). I have labeled their bulkhead connector positions, using Dave Delman's numbering scheme, and left it at that.

Dave has correctly identified the rear light ground, so I left that as is on the schematic.

The grounds in the Red bulkhead connector do not match either of my cars' wiring exactly: both of my cars have the neutral safety switch grounded through position 16, not position 14. Makes no operational difference of course, but it does matter how I label the other two bulkhead pins. Numbers 13 and 14 are ganged together, 16 has its own wire. I decided to simply label all three of them generically.

Latest revision:
4503
I'll eMail a full size version to Sean and see if he can't get it posted somewhere.

Remember that this is still a work in progress -- mostly finished, but still subject to change.

Bill Robertson
#5939

Just noticed that the way I drew the window switch grounds made it look like they share a large gauge wire from the junction. Redrawn to more accurately represent the actual configuration:
4507
I also changed labeling of the Lambda ECU to hopefully be less confusing.

Bill Robertson
#5939


What size wire ties that bulkhead common to the frame?

6 gauge.

Bill Robertson
#5939

[sean]

I'll eMail a full size version to Sean and see if he can't get it posted somewhere.


Got it and once I get out of this 6 hour retention meeting I'll get it up. My iPad is not very forum management friendly.

[Ron]

I suggest that now is a good time to merge and edit the several ground threads going on right now.

[content22207]

They're sorted out pretty well already:

This thread covers the stock setup, so it belongs in General.

Ground buses are modifications, so that thread likewise belongs in Mods.

The Resource section above doesn't need a bunch of extraneous commentary, so really the only thing that belongs there is the latest version of the schematic, and perhaps a few pertinent comments such as wire gauge from the bulkhead bolt to the frame.

Some of the same pics have popped up in both the Schematic and the Ground Bus threads, which gives the appearance of duplication, but content itself is significantly different (the same pics were just used to illustrate different points, stock versus mod).

Bill Robertson
#5939

[sean]

Ok, Bill, the one you have uploaded seem proper to me as when I upload this guy I can click on him and he expands. Does this not work for others? You actually have to click on him twice to make it expand.

4516

[Malevy]

Nice job Bill..

The one thing that bugs me about this is I have run 8GA wire from the radio bracket down to the frame bolt on at least 6 cars now, and noticed an improvement (based on the dashboard voltage gauge) in ALL of those cars.

On one car, when I put the bolt back in I missed one of the wires. IIRC, the dashboard did not work because of the wire I left off. If that radio bracket bolt is just for the radio itself, then that would not make any sense.

There is the possibility that the harness was changed at some point in production. We know there are electrical differences in the various vintages of DeLoreans.

[content22207]

If the harness changed, if was after VIN 5939 (both of my cars have a junction behind the central A/C duct).

I never paid too much attention to that bundle of wires on the radio bracket until this project. Both #2508 and #5939 have nothing but capacitors and the radio on it.

I suspect people assumed the instrument cluster was grounded to the radio bracket because the ground junction behind the central A/C duct is virtually impossible to see. I had no idea it was back there. When I tied #5939's junction into its ground bus I had to do all the work by braille -- that's how hidden it is. There are only 3 ground wires coming down the driver's side of the console, so the binnacle was obviously grounded somewhere north of the radio bracket. I guess people just assumed that one of those wires had to be it (two wires actually -- there are two grounds from the binnacle/instrument cluster).

I am open to changing the schematic, but only if the changes are proven by visual inspection. I ripped all the wrapping off #2508's harness to make it. Nearly every single wire was individually traced. There are only a couple of assumptions in the current revision:
- Individual ground wire that disappears into the dash by the passenger windshield corner (not the A pillar bundle) is assumed to the the same wire that emerges from underneath the exterior trim piece and is bolted to the fender
- Third large gauge wire leaving the junction behind the central A/C duct is assumed to be the windshield wiper motor. I have yet to find the motor to verify that it does indeed have a large gauge wire attached to it (where is the damn thing?)
- Every small wire leaving the junction behind the central A/C duct is accounted for. There is a ganged small gauge wire leaving the plate that holds the windshield wiper delay module going somewhere.

The wiring harness up & over the steering column is the only one I did not unwrap, because it is sandwiched between the metal superstructure and the dash (inaccessible). I did unwrap the harness where it passes through the firewall towards the windshield washer bottle -- there are only two large gauge ground wires in it at that point.

Believe it or not, I traced every inch of the two black wires from the Lambda ECU to the bulkhead connectors, including unwrapping the bundles all the way through the plywood bulkhead (twice!). That's no small feat. I had to do it -- those wires were obviously present in different locations but unaccounted for. I physically followed each wire to see where they went. I have no idea what they do, or even if they are in fact grounds, but that is definitely where they go (verified this morning by ringing them out with a meter).

The cigarette lighter ground is a tricky one. The wire starts towards the front of the car, then about 4-6 inches later makes a U turn back to the harness that goes to the rocker switches. Unless you unwrap the entire harness it looks like two different wires.

Bill Robertson
#5939


Ok, Bill, the one you have uploaded seem proper to me as when I upload this guy I can click on him and he expands. Does this not work for others? You actually have to click on him twice to make it expand.

4516

Still 840x1030.

This is what my 1300x1595 working copy looks like split down the middle:
45194520

Bill Robertson
#5939

[Malevy]

- Third large gauge wire leaving the junction behind the central A/C duct is assumed to be the windshield wiper motor. I have yet to find the motor to verify that it does indeed have a large gauge wire attached to it (where is the damn thing?)


It is above the pedal box..

[Ron]

Does this not work for others? You actually have to click on him twice to make it expand.
In post- 81x100
Click to Expand- 411x504
Click Twice- 411x504 but in own window
Drag to PS Pro- 839x1030

-Good Job Bill

[content22207]

Just remembered that I grabbed the ground that previously went to the shifter illumination bulb for another use. Sure enough -- it's bloody stump is still in the middle ground junction (just unwrapped it for visual verification).

As stated, this is still a work in progress. I am open to changes, but they need to be physically verified, not just conjectured:
4521

Bill Robertson
#5939

Actually that bloody stump may be for the Fan Fail/Lock Door/Defroster bulbs. I've thrown #2508's bulbs away. AFAIC they are nothing more than an impediment to console removal. I'm a big boy -- I can lock my own doors. The fan fail light doesn't do anything if you run a jumper in the fan fail socket. And I don't use the rear window defroster because it has a blistering hot engine sitting directly underneath it (has anybody ever had their back window covered with ice?).

Anyway, could somebody with those bulbs intact please verify whether or not they are grounded through the middle junction on the passenger side.

I am going outside (in the rain) to unwrap the rear junction on the driver side to see if it has a bloody stump. I seem to remember the shifter illumination bulb going up that side of the harness.

Edit: No bloody stump. I am almost positive the shifter illumination bulb used to come from the driver's side of the harness. Could someone with an unmolested car trace the shifter illumination bulb ground? I'd like to keep this schematic as accurate as possible.

Bill Robertson
#5939

Almost finished for real this time.

Took the console back out of #5939, which still has the warning bulbs that used to be in its A/C panel (coiled up and pushed out of the way). It also has the shifter bulb line. There are eleven small gauge ground wires coming out the the middle passenger side junction, all accounted for now:
4546

As soon as I figure out where the wire that is ganged onto the wiper delay chassis goes, every single ground wire north of the bulkhead bolt will have been traced.

Bill Robertson
#5939

Apparently the DML is better than DMCTalk after all -- it lets you upload bigger files: http://f1.grp.yahoofs.com/v1/0DtaTvDHrNA4go5rWN9gwEPCucsNQiF87yuexNfwAMJaaVGIwu Y7HEiDM7oa0ipcya_xfCIGY8IBwP-ey0pI76byerCXUAOftew/DeLoreanGroundsFinal6.JPG

Bill Robertson
#5939

[SamHill]

For us nonmechanical types, is it fair to conclude from these threads that
1) The cars systems were designed in isolation and then quickly married
And therefore
2) The car has twice as much wiring than it should have

Or am I wrong. The rest of us wouldn't mind some general conclusions about what your detective work means in terms of their theory of wiring this car.

[Farrar]

Given the information in this schematic I would say that the average owner should at least ground the inertia switch to a body bolt. This would be easy enough to do: remove the shifter cover plate and there's your bolt. Now just ground that junction to that bolt using a suitably large wire, perhaps 10-gauge.

... In fact, I think I might do this before I start driving the car on my new fuel pump. Although I like the idea of a ground bus, I don't have the wherewithal to make my own ground cables. (It's a shame, since I already bought the cable and lugs -- anybody wanna buy some 6-gauge black battery cable and copper lugs from me?)

Farrar

[AdmiralSenn]

Really? It's not hard. Propane torch, heat up terminal, fill with solder, insert cable, allow to cool, crimp. I just finished mine.

The hard part is spending the money, the rest is easy.

[content22207]

The rest of us wouldn't mind some general conclusions about what your detective work means in terms of their theory of wiring this car.

1) It sure is helluva lot easier to ground devices on a metal bodied car (can I hear an "Amen" from the Corvette owners).
2) DMC obviously never meant the ground junctions to be user serviceable, otherwise they wouldn't have hidden the most important one in the most inaccessible location.
3) Ganging the instrument cluster with a bunch of other devices, especially the intermittent wiper motor, was a bad idea.
4) Only one 18 gauge ground wire for all the rear bulbs was another bad idea.
5) Empirical evidence indicates the front driver side grounds are inadequate:
- Melted inertia switches
- Melted fuel pump fuses
- Erratic instrument cluster behavior
6) There are only seven 12 gauge ground wires for all the electrical devices north of the rear bulkhead (plus the rear lights, and a couple of engine mounted devices) -- a mere fraction of the copper in all those positive leads. If the ground wires are in fact adequate, they are just barely so, with no margin for connection degradation.
7) Almost the entire car depends upon the cable that goes from the bulkhead bolt to the frame. If you're going to clean anything, clean it (DeLorean owners seem to be disproportionately preoccupied with the radiator bracket bolt).
8 ) On the new & improved DMCTalk, if you put an "8" and a close parenthesis next to each other the site automatically reformats them into a smiley face.
9) Conventional wisdom that the instrument cluster is grounded via the radio bracket is just plain wrong.
10) As bad as Fords are, their wiring still runs circles around a DeLorean.

I'll add more as I think of them.

Bill Robertson
#5939


Really? It's not hard. Propane torch, heat up terminal, fill with solder, insert cable, allow to cool, crimp.

Alternative method: drill a small hole for solder to flow through, flux the inside of the connector, insert cable, heat with a torch, flow solder in.

Bill Robertson
#5939

[dn010]

Really? It's not hard. Propane torch, heat up terminal, fill with solder, insert cable, allow to cool, crimp. I just finished mine.

The hard part is spending the money, the rest is easy.




That's how I did mine, I think I posted this method earlier but it is very quick and easy, and it holds even without a crimp should you choose not to.

[Farrar]

That's how I did mine, I think I posted this method earlier but it is very quick and easy, and it holds even without a crimp should you choose not to.

Gas cylinder: $11. Soldering/brazing torch: $35. Battery crimp tool: $231.

Soldering method looks a lot better to my wallet. :)

Farrar

[AdmiralSenn]

Gas cylinder: $11. Soldering/brazing torch: $35. Battery crimp tool: $231.

Soldering method looks a lot better to my wallet. :)

Farrar

I bought a propane cylinder with head and a decent sized tank for ~$25, and honestly you can get away with a regular crimper and brute force. Alternately you could use a bench vise - not sure how much they are but I know there are crimping tools you can put in a vise.

I just used a set of regular wire stripper/crimpers. One terminal I couldn't quite get crimped enough so I stuck it in the corner of the vise and pinched it a little farther.

Don't really need anything fancy for this particular job.

Alternately you could probably rent or borrow a battery crimp tool from advance or whatever's closest.

Trust me this job is well worth it, just for the peace of mind.

[Farrar]

Alternately you could probably rent or borrow a battery crimp tool from advance or whatever's closest.

There's an idea -- I hadn't thought that such a thing might be one of the loaner tools available from a parts house. Thanks!

Farrar

[dn010]

If you go to Lowes or Home Depot, they have the small propane cylinders or [my preference] MAPP gas cylinders. These cylinders are cheap.

[content22207]

Without a proper crimping tool you're going to be just as well off with solder alone. Be sure to flux the connector so the solder will stick.

Bill Robertson
#5939

[Ron]

Body Bonding?

[content22207]

Static electricity dissipation.

Bill Robertson
#5939

[Farrar]

I could probably attempt crimping with a blunt cold chisel and a sledgehammer, but I think soldering will be the way to go, once I have the money and time. In the meantime, I am going to run a 10-gauge ground wire from that bundle behind the gauge cluster to the nearest body bolt, ensuring that my inertia switch has a good ground; I am tired of dead fuel pumps making we walk home.

Farrar

[content22207]

12 gauge would be adequate. Just cut the ground wire at the switch and tie your new ground to it there. The inertia switch is *MUCH* more accessible than that junction (at least without tearing half the car apart).

Have you been melting fuse #7? If so, your pump ground is indeed likely below par.

Bill Robertson
#5939

[Ron]

Static electricity dissipation.

Bill Robertson
#5939
Sorry, I meant where does it connect. I found several braided grounds exposed while cleaning up and replacing seals etc. Thought you might want the locations for completeness.

[content22207]

Only connection I found inside the passenger compartment was through the passenger side of the car, directly below the windshield, to one of the dashboard studs, thence to the blower motor (the negative side of the blower motor has three posts, which DMC used as a junction point). There is no wire in that location on the driver's side.

Bill Robertson
#5939

[Ron]

There are some braided wires connecting some of the body panels, for example on the fender near wiendshield to somewhere I forget right now, but I'll get a list if yours are gone and you want them.

[content22207]

I wasn't concerned about body panels connected to each other.

I traced ground wires inside the passenger compartment, every single one of which ultimately passes through the rear bulkhead bolt, and ground wires attached to the radiator bracket.

I did not trace ground wires in the engine compartment, other than those that pass through the bulkhead connectors (nee bulkhead bolt), because I do not have stock engine compartment wiring to dissect. Someone else can fill that in if they want.

Bill Robertson
#5939

[Bitsyncmaster]

It's still nice to crimp the terminal so it holds things while you solder. Not to bad if you only have one wire in the terminal but with many wires crimp it with anything.

When I made a new ground cable for my front bank of relays, I had eight 16 AWG grounds and one 16 AWG going to the junction. For that I just cut the ring off a 6 AWG terminal and could crimp all those wires together. Then is was soldered and shrink tubed.

[content22207]

No need to crimp a battery cable. Remember: we're dealing with something as large as a bolt here.

I hold the cable in a vise, drill and flux my terminal, slide it on, then flow the solder in.

Word of caution: the cable will keep wicking solder as long as you feed it in. Don't get carried away or you will end up with a solid core cable (that is even less flexible than solid copper) rather than a stranded one.

Bill Robertson
#5939

[Bitsyncmaster]

Word of caution: the cable will keep wicking solder as long as you feed it in. Don't get carried away or you will end up with a solid core cable (that is even less flexible than solid copper) rather than a stranded one.

Bill Robertson
#5939

Agreed.

Also I don't recommend soldering with the flat relay socket terminals. Unless your real careful you will get solder flowing pas the bottom part of the terminal and then your relays will not seat fully. You can test this by sticking a new terminal and a soldered terminal onto a relay and see how far they seat. You may be able to do it with brass but not with tin plated terminals. Been there done it.

[Spittybug]

While I am diligent in maintaining the electrical integrity of my car, this one eluded me... I had checked all of my ground connections and was convinced I was in good shape. I decided today, since it was a RARE low humidity, only 92 degree day in Houston, to solder all of my connectors to their cables using my handy dandy propane torch and spool of solder. Well, lo and behold, when I got to the MAIN ground; battery to frame, the bolt was in good connection, but the connector on the end of the wire was spinning on the wire! This is located right next to the passenger side TAB. CHECK THIS PEOPLE!! With time, these funny 90 degree clamped on connectors are starting to come loose from the wires. In the attached pics you see what I'm referring to, but make sure you check ALL such wires. I have pulled it out, cut an inch off the end, dremmeled the connector, reattached it to the wire and soldered the connection. BAM!

[sean]

Good catch! Folks should inspect these little guys more often too, not just the ground bolt. I've seen several in the past few years simply missing.

[Bitsyncmaster]

While I am diligent in maintaining the electrical integrity of my car, this one eluded me... I had checked all of my ground connections and was convinced I was in good shape. I decided today, since it was a RARE low humidity, only 92 degree day in Houston, to solder all of my connectors to their cables using my handy dandy propane torch and spool of solder. Well, lo and behold, when I got to the MAIN ground; battery to frame, the bolt was in good connection, but the connector on the end of the wire was spinning on the wire! This is located right next to the passenger side TAB. CHECK THIS PEOPLE!! With time, these funny 90 degree clamped on connectors are starting to come loose from the wires. In the attached pics you see what I'm referring to, but make sure you check ALL such wires. I have pulled it out, cut an inch off the end, dremmeled the connector, reattached it to the wire and soldered the connection. BAM!

That's the same that John had found and posted on his site for selling his new ground cables. Guess I better check mine. Or better yet, put a real terminal on that wire.

[Trstno1]

I know this is an old thread but does someone have a picture of the grounding junction behind the AC duct. This would be one of the last grounds I have not cleaned up on my car.

[Rich]

I know this is an old thread but does someone have a picture of the grounding junction behind the AC duct. This would be one of the last grounds I have not cleaned up on my car.

Pretty hard to get a photo of it (black on black in a dark place) but I can see mine clearly with a good flashlight. After you find it you might decide to leave it alone...

For your hunt refer to earlier posts in this thread along with Bill's schematics in the early ones. Try posts #4, 7, 9 and 10, to get an idea about it then look up to the right of the driver side footwell, left of the gas pedal and above the A/C distribution ducts, sort of in the middle. Look for a half dozen or so black wires all running in parallel into a thick, freestanding stub wrapped up in black tape. That's the junction. It's a gathering up of component ground wires connected to a main ground wire that in turn runs back to the bulkhead ground bolt according to the schematic. The junction isn't bolted to anything.

This isn't the same situation as some of the other grounds on the car you can 'clean up' by unscrewing a nut or bolt and cleaning up some ring connectors.