Wiring Nightmare
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Wiring Nightmare
Hey guys, new to the forums.
I have an 86 Camaro Z28 IROC (VIN 1G1FP87F5GL185548) that was stolen-recovered way back in the day. It has been sitting in my dad's barn, as he didn't have time to work on it. Now that I have the money and time, I picked it up as my project car.
As it was stolen, the thieves pulled the engine and trans, ECM, radiator, and oddly enough the wiper motor. The thieves snipped any wire that was connected to or even touching something near the engine. I have since rewired everything I currently can in the engine bay, but the real issue is on the interior of the vehicle.
The wiring that comes from the drivers side of the vehicle, through the dash, and goes to the ECM was snipped as well. The engine I am putting into the vehicle is a TBI 350 engine that is being reformed to carburetor (which is pretty much finished, just waiting on gaskets). As the 86 z28 IROC engines were TPI, I have a different ECM that was normally in the vehicle so the wire colors do not match up. To remedy this I need the wiring diagrams for the 86 IROC Z28.
I have seen the huge list of wiring diagrams in the thirdgen.org -> How To -> Electrical - 1986 Wiring Diagrams. I just honestly don't know where to start (Very new to this). I don't know where I would find this cluster of wires in the diagrams. I have attached a picture of the ECM plug, and the wires in case anyone can give me some insight on what wires are what, or how to figure out these wiring diagrams. I just don't know where to start!
Thanks ahead of time!
I have an 86 Camaro Z28 IROC (VIN 1G1FP87F5GL185548) that was stolen-recovered way back in the day. It has been sitting in my dad's barn, as he didn't have time to work on it. Now that I have the money and time, I picked it up as my project car.
As it was stolen, the thieves pulled the engine and trans, ECM, radiator, and oddly enough the wiper motor. The thieves snipped any wire that was connected to or even touching something near the engine. I have since rewired everything I currently can in the engine bay, but the real issue is on the interior of the vehicle.
The wiring that comes from the drivers side of the vehicle, through the dash, and goes to the ECM was snipped as well. The engine I am putting into the vehicle is a TBI 350 engine that is being reformed to carburetor (which is pretty much finished, just waiting on gaskets). As the 86 z28 IROC engines were TPI, I have a different ECM that was normally in the vehicle so the wire colors do not match up. To remedy this I need the wiring diagrams for the 86 IROC Z28.
I have seen the huge list of wiring diagrams in the thirdgen.org -> How To -> Electrical - 1986 Wiring Diagrams. I just honestly don't know where to start (Very new to this). I don't know where I would find this cluster of wires in the diagrams. I have attached a picture of the ECM plug, and the wires in case anyone can give me some insight on what wires are what, or how to figure out these wiring diagrams. I just don't know where to start!
Thanks ahead of time!
Re: Wiring Nightmare
Look for C207. The wires in the bundle won't all be on one page of the wiring diagrams. If you look closely at the connector you'll seen the pin locations are marked with letters and/or numbers. When a wire in that bundle is in the diagram it'll show C207 and the letter/number of the terminal, along with the wire color(s) and the wire gauge in metric.
So for example, in this diagram, we can see the pink/blk wire from the Engine CNL fuse goes through C207 at the pin marked F, and then continues from there to the ECM.
You'll have to track down every reference to C207 in every page of the wiring diagrams until you have all the wires identified. Fun stuff.
There are basically two connectors between the engine compartment and the rest of the car. C100 is the big square plug on the driver's side of the firewall, it's actually two smaller plugs on the engine side of the firewall, the smaller of which runs to the exterior lights in front, the horns, stuff like that, then the other connects to one end of the engine harness. The other end of the engine harness wraps around into the passenger's fender and goes through a cutout next to the passenger's kick panel, then goes to the ECM and then to C207. C207 generally has wires for everything in the engine harness that doesn't go through C100.
The actual shop manuals generally have a couple pages that show the C100 connector and it's circuits, but it doesn't look like they're on that page. If you can get your hands on the service manual or the electrical sub-manual, you might be able to give yourself a better idea of what circuits will be going through C207 by process of elimination. Otherwise you're going to be reading all the connector numbers on every page of the wiring diagrams and hoping that what you're looking for isn't on a page that didn't get scanned.
So for example, in this diagram, we can see the pink/blk wire from the Engine CNL fuse goes through C207 at the pin marked F, and then continues from there to the ECM.
You'll have to track down every reference to C207 in every page of the wiring diagrams until you have all the wires identified. Fun stuff.
There are basically two connectors between the engine compartment and the rest of the car. C100 is the big square plug on the driver's side of the firewall, it's actually two smaller plugs on the engine side of the firewall, the smaller of which runs to the exterior lights in front, the horns, stuff like that, then the other connects to one end of the engine harness. The other end of the engine harness wraps around into the passenger's fender and goes through a cutout next to the passenger's kick panel, then goes to the ECM and then to C207. C207 generally has wires for everything in the engine harness that doesn't go through C100.
The actual shop manuals generally have a couple pages that show the C100 connector and it's circuits, but it doesn't look like they're on that page. If you can get your hands on the service manual or the electrical sub-manual, you might be able to give yourself a better idea of what circuits will be going through C207 by process of elimination. Otherwise you're going to be reading all the connector numbers on every page of the wiring diagrams and hoping that what you're looking for isn't on a page that didn't get scanned.
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Joined: Jul 2006
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Re: Wiring Nightmare
http://berlinetta.info/C207.htm
have you considered an LS swap? That requires reworking the C100 and C207 plug to connect with a new LS engine harness. I think you said that you were going carb. That could also ease your wiring problems if you use something other than the Quadrajet - like a Quickfuel carb.
have you considered an LS swap? That requires reworking the C100 and C207 plug to connect with a new LS engine harness. I think you said that you were going carb. That could also ease your wiring problems if you use something other than the Quadrajet - like a Quickfuel carb.
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Joined: Jan 2006
Posts: 726
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From: League City, TX
Car: 90 Formula -- tot resto in progress
Engine: 350
Transmission: 700R4 w/ 2500 stall, by Owen @ ARD
Axle/Gears: 3.23 posi disc
Re: Wiring Nightmare
Not sure about the 86, but here's my experience w/ my '90 Firebird TBI.
The engine compartment wiring harness was one huge unit, with the C100 connector on the drivers side,
and a large bundle that goes through the passenger side fender well, that connects to the ECM.
It was built for ease of factory assembly, not maintainability.
If you're going to switch to a carburated engine, this part of the original harness is unnecessary.
**** that I was, I dissected the single harness, into the ECM components (through the passenger side),
and the general engine compartment harness through the C100 connector on the driver side.
(I added several circuits through the C100 connector. ****, etc., but my engine compartment is super clean.)
If you go this route, you only have to repair all the C100 connections. A shop manual that includes wiring
diagrams will be useful, if not mandatory. It will take some time, but it really is do-able.
Good luck, and keep us posted.
The engine compartment wiring harness was one huge unit, with the C100 connector on the drivers side,
and a large bundle that goes through the passenger side fender well, that connects to the ECM.
It was built for ease of factory assembly, not maintainability.
If you're going to switch to a carburated engine, this part of the original harness is unnecessary.
**** that I was, I dissected the single harness, into the ECM components (through the passenger side),
and the general engine compartment harness through the C100 connector on the driver side.
(I added several circuits through the C100 connector. ****, etc., but my engine compartment is super clean.)
If you go this route, you only have to repair all the C100 connections. A shop manual that includes wiring
diagrams will be useful, if not mandatory. It will take some time, but it really is do-able.
Good luck, and keep us posted.
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