dbergair

Hello all. Me again. How do I know if my 85 has the right engine wiring harness? Mine was all hacked up. I bought one from an 85 with an automatic and my 85 is a manual. I was told they are the same. The color coding at the ECM is different. My friend has the FSM but I wont get my hands on it until friday. My old harness has 7 wires to the trans and the one I bought has only 5. Is there a P/N on the harness somewhere? I posted this question on this forum but I cannot find it. I am not too tech savvy. I appreciate the help and am getting excited to drive this thing.

WVZR-1

Here's the original thread you mentioned:

https://www.corvetteforum.com/forums...onversion.html

I mention that '85 only uses the same harness for AT & MT BUT that the ECM harness is different for each. The engine harness is only that harness that plugs into 1/2 of the C100 connector.

I don't know what you're calling "engine harness" but here the actual C100 with the lighting and ENGINE PIN-OUT

Post a snapshot of the harness you bought laid out on a bench with end views of the mating connectors if you can.

WVZR-1

If your harness looks similar to this it's an ECM harness you've bought and this image I believe is for at '85 (A4). The differences are in the car at the connector C260 or C261 (in the second image). Dependent very much on "talent" it's seems likely that the harness as needed could be maybe stripped from the loom. We've done similar on many projects. Can you? Don't know.

If all of the wires at C260 match the wire colors at the transmission they very well may be in the loom with no "splices" to under-hood components. Might be very difficult to get through the pass-thru grommet. I'd say it could be done and maybe not very difficult. Creating a 4+3 harness and switches as you mentioned I'd think a last resort.





In the snapshot there's a white piece of tape wrapped around the harness near the end of harness inside of the car. If the harness you bought has that same wrap what is the number on it? 4 digits maybe.

Here's an image of routing that might make it easier to sort.

hcbph

Does some place like Painless sell a replacement wiring harness? If they do, it might be the safest solution.

confab

These are from my Alldata for 85, Manual trans. So they should be right.

Do they help?

confab

PS: Just from personal experience: Excepting things like fire, I have always had much better, quicker and cheaper solutions by properly repairing a harness as opposed to replacing it.

Good soldering techniques and heat shrink tubing has repaired a lot of stuff that would have been a major, major hassle to rip completely out and replace.

IMVHO.

dbergair

here are pics of my harness

WVZR-1

OK - that confirms ECM harness. Are both harnesses removed from the car yet? If not are the connectors in the car unplugged yet? If yes it might be interesting to post the wire colors and the cavity ID (A - F) of the C260 connector in post#3.

On the harness you've bought there should be a 3 cavity connector rather than the 6. What are the wire colors and cavity ID for those?

To maybe ease your swap the splices in my image post#3 may be important to consider. On all of the in car connectors I'd make notes of each with wire color and cavity then take snapshots also of each. It may be very important to sort those differences before doing anything.

I don't know what FSM you have but the WIRING DIAGRAM 7 is maybe the key to sorting it. There appears to be ECM connector repining that will be required.

With a first year and also an ONLY year how accurate are the wiring diagrams? You've got both so compare, make accurate paper notes and document it all with snapshots.

I think I get it!

Make sure you understand how to properly un-pin terminals and in your case get the proper removal tools.

Where are you located?

****If you're very NEW to this you might just use the purchased harness as a reference, either buy empty connector shells for what you can, swap those that you can't buy new and do a repair of the under-hood section where I imagine all of your issues are. User "CONFAB" mentioned a repair as well and dependent upon your talent and understanding of the diagrams etc. I'd maybe consider the same.

dbergair

This helps a lot. I will keep you posted. I am going to buy a FSM but in the mean time would you have the diagram that includes the ECM pinouts and schematics? I believe in the FSM it is quite large. Thanks again. This car has had a rough life but i feel like I have rescued it. Also my friend has the FSM for a 86. Are the wiring diagrams the same? Thanks

WVZR-1

'85 is a ONE YEAR ONLY ECM and configuration. An '86 FSM will be of no value.