I have an 87 IROC 305 TPI wiring harness. I'm trying to chase down a missing ground on my headlights which is causing the parking lights to ground through the headlights.

I have the schematics manual for this harness but I am having a hard time identifying this connector.

The connector which is attached, is a black connector with three cavities two of which are used with the middle being empty. The wires are a tan and dark green. The connector is near the bulkhead connector around the brake booster and relay center on the driver side firewall.

Any help would be appreciated thanks.

 

I don't recognize the connector, sorry.

However, it is not material to the issue at hand, namely, odd light behavior.

If you suspect a grounding problem involving the lights, the best way to resolve it, is to start at the light that doesn't seem to be working right, and trace the black wire there, back into the harness, or wherever. The black wires should either eventually all come together, or they should start at one light that has a single black wire which should go to some other light where that black wire meets another at that one's plug and that wire goes to another light similarly all in a daisy chain, and eventually you should come to a black wire that has a ring terminal on it and is screwed to the chassis somewhere. Find & repair any broken wires, bad connections, etc. anywhere between the misbehaving light and the actual ground connection. If the problem is where 2 black wires meet in one plug, it may be easiest and most effective to simply replace the plug, cutting the old connectors completely off in the process, and splice the black wires all together, with rosin-core solder, heat-shrink tubing, and electrical tape over that.

 

Thanks for the the tip there. I've been digging through this harness a bit more and as it turns out I'd left out some information that I didn't think was actually pertinent which it is.

I installed LED high beams and low beams and what's actually happening apparently is something called ghosting. Essentially when I turn on my parking / marker lights and given that they share a ground with the rest of the headlights a little bit of voltage bleeds into the LEDs turning them on very very faintly.
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Enough enough so for at least the high beam indicator to always be on when the lights are on.

so now I've got to figure out how to stop the ghosting I would prefer not to put the halogens back in.

​​​​​​if anyone has any ideas on the ghosting issue as they read this thread please feel free to chime in.

Thanks.

 

Usual cure for that is resistors across the lights. LED tail & brake lights often require such things.

 

Got it thanks.

I think I should be able to measure the voltage leaking and do some math to bring that down to zero.

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There's not really any "math" involved. Or at least, only very basic.

The issue with LEDs is, they have relatively high impedance across themselves until the voltage reaches some threshold; for most currently available white ones, it's in the 2VDC neighborhood. Which means, to the whole rest of the electrical system, they look like they aren't there, if the voltage impressed across them by whatever means, doesn't reach that threshold. It will require a certain amount of current to flow through them to bring the voltage drop up to that point. If there's something in the circuit that's designed to "think" that the light bulb is near a dead short to ground when turned off, it can be "confused" if that condition is not met.

The resistor thing is often used for turn signals, to prevent "hyperflashing". (you know, that annoying thing that so many of the kiddie-toy imports have, where they flash at about 5 flashes per second) I put LED tail lights in my truck, and of course it did that; so I got a $$flasher$$ specifically for LEDs that was smart enough not to do that; only then did I realize that my cruise control ALSO didn't work. Turns out, it relies on the near-dead-short electrical appearance of the brake light bulbs, to tell it when the brakes weren't applied... but the LEDs didn't provide that. The mfr of the lights provided 4 resistors, with the right connectors so they would just plug in, one for each light; as it happened, putting in just one, on one of the brake lights, fixed it.

I'd suspect you need something similar. If you study about LED TSs and all the work-arounds, I think you'll see what's going on in your case. Same thing, just different light bulbs. If you're electronically inclined you might be able to measure the current that needs to flow through the headlights when they're off, and choose a resistor that (a) brings that down to some arbitrarily low voltage, say, 0.2 VDC; (b) doesn't consume SO MUCH power that the efficiency advantages of the LEDs aren't thrown away; and (c) is large enough to dissipate whatever power is necessary to be dissipated when there's 14.x VDC across it, when the lights are on.

 

I went and got my Original 1987 Camaro Shop-Manual (from GM in 1986) out of my collection of MINT-Condition 1st-Edition GM manuals.

Please post more photos of the connector from different angles.
I at least need to see what the terminals look like inside the connector body to try and identify it.

 

Just to double check...

Your vehicle should have the letter "F" as the 8th digit of the VIN: meaning a 305-CID/ 5.0L Tuned-Port Injection engine with RPO: LB9
If your vehicle still has the RPO sticker on the underside of the center-console glove-box lid...
Look for the "LB9" RPO as confirmation.

Thanks, I can't wait to see some more photos of that electrical connector!

 

Hey sorry for the delay, I saw your reply late last night.

Here are a couple extra pictures.

And yes the engine wiring harness was from my old 87 305 TPI IROC.

At first I thought this was connector 216 but that one is above the steering column so I'm not quite sure what this one is for.

Thanks

 

Isn't that for the wiper motor?

 

No, I don't think so, the wiper motor in the '87 is like a six-pin connector and the washer fluid pump plugs into the housing as one piece.

According to my electrical manual the wiper circuit has a dark green and gray wired connector where this one is dark green and tan.

 

I am not done looking yet...

However, from what I have been able to look through so far:

This looks like is could be connector "C111".
It is a 3 terminal connector body, that has only 2 terminals populated (center terminal unpopulated).

It has one TAN wire that goes to an oil-pressure gauge, or a low oil-pressure warning-light if the vehicle does not have a gauge.
It has one Dark-GREEN wire that goes to the ECM whenever the air-conditioning compressor-clutch is engaged (usually to raise idle speed).

Let me know how this looks on your car...
I will keep hunting if this is wrong.

 

Note: there should be a mating connector somewhere in that same area...

Same wire colors and positions.

 

I think your spot on.

Little background on this project of mine.

​​​​​ I bought a 91 Z28 roller body from Arizona through Hawks Motorsports.

I took everything from my 87 including the wiring and installed it in the 91. That is body wiring engine wiring everything all the wiring is from an '87.

The oil pressure gauge didn't work it first I couldn't figure out why so as a stopgap to get the gauge working I ran an extra lead to the gauge cluster.

This unplug connector perfectly explains why that did not work. Unfortunately I seem to be missing the other connection I'm not quite sure where it's supposed to plug into but I will do some more investigation on the harness itself.

thank you for finding out what that was I really appreciate that cuz that explains a lot.

I got to get a battery for my multimeter and I'll start doing some continuity test and wire tracing to figure out where I went wrong and the install.

Happy New Year everyone.

 

Awesome! You are most welcome!

I spent a few years in the Delphi connector systems division, during a long run as an Engineer for General Motors...
I am glad to see that I have still retained some of the Delphi connector knowledge!

 

The 87 wiper motor has a plug into the controller board, and another into the motor. I'm not sure, and I don't have my reference library here, so I'm just throwing it out there. The one fuzzy pic of my 87 that shows that connector, it looks like it's between two harnesses in that position. I'd check the car, but it's across town in storage under a cover and I won't have a chance to look at it any time soon.

Good luck!