No reverse lights. More wiring assistance needed.

[stealthee]

Alright guys, I have been trying to get this figured out over the last few weekends and I am at a loss.

Upon doing initial diagnosis of things on the car I found a few things not working. The last thing I have to correct is these reverse lights. I have power at the fuse, but no power at the plug on the trans. To make things even more confusing I no continuity from the trans plug to the plugs at the reverse lights.

I've looked over the schematic and only see 3 plugs that would be at fault. I wasn't able to locate the 19 pin plug on the passenger side corner area of the dash before I called it quits. The other two plugs are on the junction box above the fuse box and other than trying to get a visual on them being plugged in I did not get to test them because I couldn't figure out a way to get to them without removing the whole dash.

I've literally got my car half disassembled again. I pulled the fenders back off hoping I could get to the plugs through the holes that the body harness passes through. I pulled my glove box trying to find the 19 pin plug in that area.

I'm ready to pull my hair out. This is the last of the issues I need to fix before I can really start moving forward in leaps and bounds. Hoping someone can offer some help before I can get back to the car.

[stealthee]

Additional info to help you hopefully help me.

The diagram is on page 8-321 of the electrical manual I have.

https://i.imgur.com/4ZXQU4F.jpg

C-82 and C-77 are both on the back side of the junction box above the fuse box under the dash.

C-29 is around the passenger corner area of the dash.

F-19 is in the hatch, F-18 would go to the reverse lights on a Stealth. The other ones I didn't mention are obvious.

I did poke the wire where it runs along the drivers side body harness and there is continuity there to the reverse lights.

[j2k4]

I hope your hair survives, Brian.

I also wish I was a better electrical-troubleshooter...

[Steve '92ES]

Do you have a connector B26, for the auto transmission? (I don't know if they delete the unused connector or just leave it unplugged).
If it's there do you have power on pin 10? Connection to the bulbs on pin 5?
I wouldn't worry about C29 just yet, not until you figure out why there's no power at the switch.

[95gto]

C29 should be accessible once the glove box and the plastic cover for the glove box (the part that holds the light bulb) is removed. The cover in question is seen in the lower left of the first picture in this ebay listing for a glove box:
https://www.ebay.com/itm/3000gt-stealth-glove-box-gray/132933353039?hash=item1ef371fe4f:g:t9oAAOSwsyZcT1r W

Once the cover is out of the way you can reach over through the dash to the top of the passenger side kick panel area.

[RealMcCoy]

Occam's razor... What is the likelihood of two separate issues over that of a single problem with multiple symptoms?

Your problem is going to be in C29

[stealthee]

Appreciate all the input guys. Super stoked to see my two favorite electrical whizzes in here. Levi I did remove all that, but thanks for your assistance either way.


Do you have a connector B26, for the auto transmission? (I don't know if they delete the unused connector or just leave it unplugged).
If it's there do you have power on pin 10? Connection to the bulbs on pin 5?
I wouldn't worry about C29 just yet, not until you figure out why there's no power at the switch.

Steve I do not have B26. Just the standard 2 pin plug B-25.


Occam's razor... What is the likelihood of two separate issues over that of a single problem with multiple symptoms?

Your problem is going to be in C29

Ok, so to confirm what I found when I removed the glovebox was C29 I grabbed my old harness when I was in the shed and located it on that harness. It is the only 19 pin plug in that area.

Where my confusion starts is the wire coloring. I tried to educate myself a little more on schematics and I learned a little, but there is no red wire with blue tracer at that plug. There is a blue wire with red tracer though. (Can't remember which pin it was off the top of my head) But if I am reading the schematic right then I should be looking at pin 11 on C-29 right?

I need to grab my meter from up at the garage where the car is and do continuity testing on the spare harness then that will give me a place to go when I am upside down under the dash. Once I figure out what wire is coming from the plug then I can start figuring out why I don't have continuity to the lights, then from there figure out where my power is. Worst case I will jump accessory power into the harness if I can get continuity fixed. I probably won't get to do much of anything until at least Thursday.

Part of my issue is I don't know if I am diagnosing a previous issue the chassis had (because if you remember this is a "new" chassis) or if I am diagnosing an issue with the engine harness that I purchased off of Greg (DrGonzo) some years back. So both parts are new to me.

As I typed that I go an idea and tell me if it is stupid. If I take my extra harness up to the garage and plug in just C29 and the reverse plug to the reverse switch I should be able to confirm if the issue lies in the engine harness that is in the car right? So if the reverse lights light up then the issue is in the engine harness. If they still don't light then I am still searching for an issue in the body harness?

I'm rambling, it's late, so I will leave off there. Again, all the help is appreciated. If I can get through this issue I can reassemble everything I took off and resume with making progress on the car. Hoping to take it to The Shootout this year, whether it is still 4 colors or not.

EDIT: I'm back almost an hour later. I did some quick searching to see what else C-29 powers. It looks like it has something to do with the MFI relay, cruise control, and HVAC. The DCC works, the car runs, so those work. I haven't take it for a ride, but the cruise control lights up so it has power. This issue is going to be the death of me. LOL

[RealMcCoy]

I think I see a potential problem... I bet you got a 2G 3000GT harness mixed in there... The Stealth manual available online was a for 94 only, so I don't know if it changed for 95-96, but that diagram we've been using is only good up to 93 in the 3K. After that they moved those circuits to C30.

[stealthee]

Well then. I have a 94/95 SOHC harness in the 1g 3000gt. Your explanation seems to explain a lot now.

See, this is why I was glad to see you post. I never would have figured that out.

I guess now I have to figure out how to make my own jumper harness.

[RealMcCoy]

Well then. I have a 94/95 SOHC harness in the 1g 3000gt. Your explanation seems to explain a lot now.

See, this is why I was glad to see you post. I never would have figured that out.

I guess now I have to figure out how to make my own jumper harness.

I think the likely explanation is that the 94 stealth manual is just wrong, and they all changed at the same time... That would explain the issue, as you would have a 1g/2g mismatch. Regardless, C29 and C30 are right next to each other, I suspect you'll be able to de-pin the connectors and move the wires around to where they match up...

[stealthee]

I think the likely explanation is that the 94 stealth manual is just wrong, and they all changed at the same time... That would explain the issue, as you would have a 1g/2g mismatch. Regardless, C29 and C30 are right next to each other, I suspect you'll be able to de-pin the connectors and move the wires around to where they match up...

Never thought about that. Thats a good idea. Much appreciated. I feel way more confident about this now and actually feel a liitle weight lifted off my chest knowing I'm not completely crazy with this thing. When I actually get back to it and get it working I'll post back and let you know.

[stealthee]

Just to confirm your suspicions I got in the she real quick when I got home and verified that the wires for the reverse plug are indeed in C30 on the 2g harness. Now I just have to figure out the best way to make it work without causing myself too much hassle for future plans with the car...

Thanks again. I'd probably have eventually figured it out once I got a chance to continuity test things, but no way it would have been figured out this quickly without your help.

[stealthee]

I still didn't get to make my jumper due to a host of business and other issues over last weekend but I go to minute to jump power to the red/blue wire in the body harness.

https://i.imgur.com/8ofye4F.jpg

Due to the harness confusion I think my fix is going to be to depin the red/blue wire from C30 and make a jumper to put it into C29 so it connects with the red/blue coming from the switch. Then for the black/white wire I may just run my own accessory power wire into C29 just to make things easier.

It's going to be a pain regardless because there isn't much slack in the harness to get to things easily.

Thanks again.

[stealthee]

I was able to fix the reverse light issue "correctly." What I did was depin the switch wires from C30 on the engine harness. I grabbed my extra body harness and depinned two of the correct size pins and a length of wire. I had to depin one random wire from C29 because it mated up with the signal wire going to the reverse lights. I'm not sure what it correlates to but I'll loom into it later. Anyway, I inserted my wires I had depinned into the harness in their proper spots and crimped some male spades on then inserted into the two female spades I depinned from the engine harness. Did a quick test and it worked as it should. I installed some heat shrink over the spade connections and breathed a sigh of relief.

Thanks yet again. Because of your help I was able to get this fixed and move forward. I got a lot accomplished once this was fixed. This will be easy to undo when the time for the next stage comes too.