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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Hey guys I'm new here and need some help. I have an 89 iroc 5.7 that was converted to carb by the PO. I've rebuilt the motor and trans with really nice parts and now my engine bay looks terrible (besides the shiny new engine). So I want to clean it up and the wiring harness needs to go. I've removed the harness from the passenger side and this is where I'm lost. How do you separate the two harnesses? Which wires/plugs do I keep? I know the drivers side harness is the body harness I've been researching this topic for a week. I need help, thanks
I have the same issue with my 88, Im putting the TPI back on it and have almost quit as i haven't touched it in a year because i need help figuring it out..
Dude I know it's ridiculous. Ripping it out is one thing, I can't imagine trying to reconnect all that monkey ****. I've been searching on here nonstop for a week now. I've got most of it figured out I just can't seem to figure out where the body harness starts and the tpi harness ends. Good luck man
I recently pulled the engine harness out of my 89 TPI Camaro. If you've already pulled the ECM and the pass-through on the passenger side you've got the hard part done. OR... maybe I don't understand your question. The harness has another connector on the driver side, outboard of the brake booster. Use a 7mm socket to unbolt that connector and you'll soon realize that it's actually two connectors in one. Separate those, because one is for your headlamps, the other goes all over the engine compartment. Starting from the driver side, it runs forward to the washer pump and Evap charcoal canister valve, it also goes to the Temp Gauge sender, the alternator, the wiper motor, the wiper module, several relays near the brake booster, as it goes across the car, it grounds on the back of both cylinder heads, has a couple of connections for the blower motor, one for the underhood lamp, then runs forward to the starter motor, and also up near the radiator for the cooling fan relays and battery connection. There's a great write-up on removing all the wiring you don't need.
If you would rather, I know earlier this year he was building harnesses for people, then he got busy with things for a while. You might email or PM him if you want to just buy a new harness. I'm not sure what he charges, but I will bet it's reasonable. I've got the knowledge and access to some tools so I thought I'd do it myself. It has taken so much time and probably what I would expect he charges to make a new harness, so I'd suggest to go that route if you're thinking of replacing wires and terminals. If you're just going to clean up your harness the link above is amazing. I was a little hesitant to go cutting all that stuff, but he's got it really accurate.
Last edited by Lurbie; Oct 7, 2015 at 08:17 PM.
Reason: Add link to harness prep thread
Oh, I'll also add that it wasn't too difficult to remove all the wires from the passthrough. The sealer in there is old and feels like a dry gum eraser (remember those from the 80s?) If you use several screwdrivers and a gasket scraper it will pry apart without breaking, then you can easily scrape chunks of the gummy sealer out and reuse the passthrough.
Lurbie, thank you! I've already pulled the harness through the passenger kick panel and fender. I've also pulled out the ecm. Then I removed all the sheathing and got a little overwhelmed. But I should be able to figure it out from here. Thank you for the breakdown
I should also add that I've driven this car once, the day I got it three years ago. It went immediately into the garage for some carb adjustments. Which quickly turned into a complete engine and trans rebuild. Its a nightmare trying to figure out which wires/plugs go to what. I'm sure this is why the PO hadn't removed the harness in the first place
Mines an 88 but i have an 87 harness in it now there's an extra plug with the ecm plugs that my 88 dash doesn't. But my 88 has a crack between the Ac and radio bezel anyway so i plan on swapping that dash and the heater core while its out. But anyway the 87 dash has the other side of the plug that the engine harness does so i hope it will prime the fuel pump and start the car.. that's where i quit last year,
Mines an 88 but i have an 87 harness in it now there's an extra plug with the ecm plugs that my 88 dash doesn't. But my 88 has a crack between the Ac and radio bezel anyway so i plan on swapping that dash and the heater core while its out. But anyway the 87 dash has the other side of the plug that the engine harness does so i hope it will prime the fuel pump and start the car.. that's where i quit last year,
There were differences between 87 and 88, most notably the fuel pump power feed. If you plan on changing out the harnesses anyway, OK, but it isn't necessary to do that. The extra connector has pins that need to be moved to the C207 connector in order to get it to match up. You may also have to add pins to the C100. I have repinned my 87 dash harness to match the 89 engine harness that I just installed. If you get the diagrams for the C207 and C100 connectors for both years, you can see which pins you need to move/add. Good luck.
As for me, I haven't finished the job yet, but I did find all the info I needed on TGO by searching the boards.
