MASTER - parts cross reference list

[content22207_2]

Just so everyone is clear: if you fill an electric motor full of water, it is by definition full of water. Doesn't matter whether the lead is positive and the chassis is negative or vice versa -- both will be under water.

Bill Robertson
#5939

[DMCVegas]

Exactly what does Robert think happens if you touch a power wire to a negative ground housing?

Tomato tomato....

Bill Robertson
#5939

Well if you touch a power wire to a negative housing, you create a dead short for that particular power wire and it's respective circuit, obviously. Not including any other risks to it.

If you have a positive housing, you're creating a safety concern for the vehicle if anything else conductive touches it. It creates another short, but one that flows in the opposite direction. It may be a dead one that blows a fuse, a resistor, or simply trips a circuit breaker. Or it can also transfer power on that unintended ground to generate heat. Which can damage wiring, or even risk a vehicle fire.

If your DeLorean was the victim of an electrical fire, and I made you a deal where I was able to completely restore the vehicle back to it's previous condition before it ever caught fire for $76, you'd take me up on that. For $76 it would be like nothing ever happened to your car. You'd be crazy not to take me up on that offer, right?

So why would anyone cheap-out on non-OEM parts that fail to function as intended, and risk their safety? Because that $76 price difference is what you're "saving" by not buying the correct parts, but it's costing you a whole lot more on your risk management side.

[content22207_2]

Exactly what part of "non-conductive" isn't clear?

The entire car body is non-conductive. That is why the nice people at Lotus ran ground wires everywhere. If you lay a bare positive wire against the fiberglass underbody, absolutely nothing happens (outer stainless panels are grounded from the factory for static discharge, but even those wires are sometimes missing. There's only three grounding points anyway).

It is obvious this simple solution is driving you and Josh to distraction. My recommendation therefore is for you to buy your blower motors from Houston. I will continue to get my free replacements from Autozone (after the first $16.99 any replacements are free). PM105 is a stock item that doesn't have to be ordered in (cross references to a large number of 1980's GM products).

Bill Robertson
#5939

[content22207_2]

If you lay a bare positive wire against the fiberglass underbody, absolutely nothing happens

Clarification: if you lay a bare wire of any sort -- positive or negative -- against the car body, absolutely nothing happens. The fiberglass underbody, including integrated dash superstructure, is electrically neutral.

Bill Robertson
#5939

[DMCVegas]

Did I say once that the underbody was conductive? Please, enlighten us all and show us where exactly I ever made such a ludicrous claim. Re-read and you will clearly see where I clearly specified the risk in reference to conductive materials.

Using this part is a hazard, plain and simple. There is a very clear reason as to why the motor housings, even on a fiberglass car, are designed to be negative: Safety.

The only distraction here is you, Bill. You prejudiced against myself, Josh in this case, and a whole slew of other people from past conversations where our only "crime" is calling you out on your misinformation. I am all for saving money, and doing things economically. My goal is to keep cars on the road, and ensure that people are able to do that in a safe manner. But safety is paramount in all aspects. If there is an aftermarket part from even a non-DeLorean vendor that can save money, or even better exceed OEM specifications, I am all for that. But when it is a sub-standard replacement such as this blower motor, then I cannot abide by it's recommendation.

You are trying to demonize anyone who is a threat to your illusion of somehow being a DeLorean messiah.

Sometimes parts are more expensive due to mark-ups, and sometimes they're simply more expensive because they're the unique, rare components which you must use.

You're trying to first put words into my mouth, and second, ridicule me for paying a higher price to DMCH, and use that as some sort of character assassination against me in order to invalidate my position on this. This isn't an opinion, Bill; it's a fact. If you're not happy about the facts that run counter to your own invalid opinions, either take it up with the laws of physics and see if you can seek a judgement in your favor to get them repealed, or take the time to learn why you're wrong.

Sometimes you've just got to buy the correct parts, even if they cost more, to get the job done right. There is nothing wrong with that as it ensures your safety and the preservation of the vehicle.

[dn010]

Clarification: if you lay a bare wire of any sort -- positive or negative -- against the car body, absolutely nothing happens.

The car body or underbody?

The stainless skin of my car is grounded via a ground wire that is glued underneath the windshield. Touching a +12VDC from the car to the panel will not end well.

EDIT: I now see you stated above "underbody". Disregard my post.

[content22207_2]

The stainless skin of my car is grounded via a ground wire that is glued underneath the windshield. Touching a +12VDC from the car to the panel will not end well.

That wire grounds the hood and fenders (assuming jumper wires between them are still intact). From the factory it passes underneath the windshield to one of the dash pad mounting studs (electrically neutral), then to the blower motor (EEK!), then to the rear bulkhead bolt with the rest of the car body grounds.

Quarter panels and T panel are originally grounded to the back of the frame with two wires bolted in the corners by the rear fascia (T panel is grounded by laying against the quarter panels -- no jumper wires like the hood and fenders).

Believe it or not the doors are electrically neutral (no joke: try ringing them to ground).

Bill Robertson
#5939

[DMCVegas]

Believe it or not the doors are electrically neutral (no joke: try ringing them to ground).

Bill Robertson
#5939

Actually, no, I don't believe you at all.

Because you see, the doors actually ARE grounded. The ground wire is provided inside of the Door Wiring Harness. It attaches to the Door Lock Solenoid on the rear bolt, which in turn grounds the rest of the door.

ALL metal body panels on vehicles must remain grounded at all times. This prevents static electricity from building up so that it doesn't knock you down, or in rare cases even kill you.

[content22207_2]

If Lotus used the door lock solenoid as the ground point that would explain why both my cars have electrically neutral doors -- I've removed solenoids from both (I just lock the doors like a pickup truck).

Does illustrate electrical weakness of a non-conductive car (like the Corvette) -- a maze of jumper wires substitutes for the ground plane. A metal bodied car is a gigantic ground plane -- anywhere you drill a hole (and perhaps scrape off some paint) is a known good ground, battery to body cable permitting. Lose one ground point on a plastic car and whole sections of the ground plane can disappear.

(Of course lack of conductivity is what keeps me from immolating myself with that Gosh Awful Autozone blower motor...).

For the morbidly curious, these are DeLorean ground points I've been able to trace out on my own cars (obviously all the K-Jet engine grounds are missing, and apparently there are details in the doors somebody may want to add. ECU tray ground has been added since earlier postings of this schematic):

GroundSchematicTop.jpg
GroundSchematicBottom.jpg

After this schematic the rear bulkhead bolt is grounded to the frame by a cable under the coolant expansion tank, then to the battery via the cable attached to the trailing arm bracket.

Bill Robertson
#5939

[DMCVegas]

If Lotus used the door lock solenoid as the ground point that would explain why both my cars have electrically neutral doors -- I've removed solenoids from both (I just lock the doors like a pickup truck).

So once again a "problem" with your car is a result of your own inadequate tinkering. Are you not seeing a pattern here too?

Does illustrate electrical weakness of a non-conductive car (like the Corvette) -- a maze of jumper wires substitutes for the ground plane. A metal bodied car is a gigantic ground plane -- anywhere you drill a hole (and perhaps scrape off some paint) is a known good ground, battery to body cable permitting. Lose one ground point on a plastic car and whole sections of the ground plane can disappear.

Actually, you're wrong again.

First, there is no "weakness" here. Using your logic it would make more sense to live in a metal tool shed run off of DC power in order to avoid all the pesky extra wiring involved. Even on a traditional all metal vehicle, you still have dedicated negative wires which bolt to ground elsewhere thanks to plastic bumpers, trim, interiors, etc. They're in all honesty no different than a DeLorean. Even IF components were immediately grounded directly where they were located in a vehicle by their mounting hardware, the metal sections still have common paths to ground which can be interrupted as well, and thus the entire ground plane can be severed even on a traditional vehicle.

Second, make no mistake, despite being made out of far more conductive materials, you're still going to have wiring harnesses in modern cars with a similar, if not the same design as the DeLorean with common, shared, and relocated ground points. Cabs of trucks are mounted from the chassis by way of rubber isolators, and thus are not automatically grounded. So a ground strap must still be installed between to two to provide a path to ground. If that strap gets disconnected, you've just wound up with the exact same complaint you just made about DeLoreans and Corvettes. So once again your words have proven your arguments to be invalid.

Otherwise if all the wires in a harness are too intimidating, you're always going to be having problems. Especially if you keep hacking away at vehicles without understanding them first. Exactly how many years now have you been erroneously telling people that the doors in their vehicles were not grounded from the factory because you didn't understand what you were looking at? Better yet, what else have you been wrong about, Bill?

After this schematic the rear bulkhead bolt is grounded to the frame by a cable under the coolant expansion tank, then to the battery via the cable attached to the trailing arm bracket.

Again, hardly any different from most, if not all, modern cars that utilize common paths to ground for multiple components. Just another straw man argument to try and deflect criticism. But let's get back on track with that right here:

(Of course lack of conductivity is what keeps me from immolating myself with that Gosh Awful Autozone blower motor...)

No, the fact that you've not yet grounded anything to that housing is why. Reversing those wires to energize the external housing is dangerous. It doesn't matter if the housing, nor even the underbody are non-conductive. There are plenty of other wires & surfaces under the dashboard which are. So if someone is working around that housing, if you or a passenger stuff some items into the passenger footwell, or who knows what else could cause it, there is a significant risk of shock, and/or fire.

Don't be stupid and risk your safety for a few dollars. Install the proper part the first time and this won't be a problem.