Hey guys, need major help!!! Just finishing my 88 fiero rebuild...my mechanic is saftying my car and also checking the electricle to make sure I did everything right...I bought an 88 fiero frame with the front wireing harness already installed. I then connected it to my 86 v6 engine wireing g harness from m old broken 86 fiero. So basically I took an 88 front wireing harness and Plugged it into an 86 engine harness at the c30 connector at the back by the battery. My mechanic informed me that the pins don't match up...(sssshhhii&$) and the starter circuit doesn't align bcc of the difference. Now he says he can wire past it NP. But doesn't know without doing some research how many OTHER wireing differences there might be...

So again, 88 front harness into and 86 rear engine harness, what r the differences (mods) that have to take place???

P.s. the 88 harness is out of an 88 gt auto. The 86 engine harness is out of an 86 se manual. I now have an 88 gt 5 speed getrag car that these 2 harnesses are currently in... Thanks guys. Really need some help here

Does noone know???

Copy this and print it for your mechanic

http://www.gmtuners.com/fil...203_C500_pinouts.pdf

All 2.5 & 2.8 body harnesses are the same for 85 - 88 years as far as the engine pinning with a few exceptions. Ignore the 84 exceptions.

The 85 - 88 body harness puts the starter wire on a different pin depending if the harness is AT or MT. (that is the problem that you are finding) The engine harness has to match up with the body harness in this regard.

On some 85 harnesses C500 A1 is used for the trunk release. 86+ has this wiring not running over the engine harness. This shouldn't even apply to you.

The harness will work fine once he changes the pin on the engine harness. The pin on the engine harness can be depinned and moved to the correct location. You have to FIRST remove the WHITE pin secondary retention fork from the side of the C500 connector. This fork is sometimes buried in black gunk. It is on the side of the ENGINE harness connector. Remove the hood and then scrape with a small screwdriver and you will see it. Then use a depinning device to untang the starter wire. It will pull out the back gently after being detanged. After you pull it out. bend the tang back up and put it in the right spot. Put the white fork back in and put the hood back on.

You won't have a clutch safety switch unless you add it. You also won't have a 'shift' light since they weren't used on 88 Fieros.

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Someone else doing the same thing - pics and everything too - https://www.fiero.nl/cgi-bin...8863&style=printable

[This message has been edited by phonedawgz (edited 07-13-2013).]

quote Originally posted by phonedawgz: Copy this and print it for your mechanic http://www.gmtuners.com/fil...203_C500_pinouts.pdf The 85 - 88 body harness puts the starter wire on a different pin depending if the harness is AT or MT. (that is the problem that you are finding) The engine harness has to match up with the body harness in this regard.

I ran into this same issue doing my auto to manual swap on my old 3.4 coupe.
I chose to move the starter wire in the "car" side of the C500 instead of the "engine" side. My only reason for doing this is so that if another manual engine/cradle was ever installed in the car, it would work as is, with no surprises.

quote You won't have a clutch safety switch unless you add it. You also won't have a 'shift' light since they weren't used on 88 Fieros.

Also, your "trunk popper", if you have one, will be live all the time, in any gear, whether the brake is set or not.
On automatic cars, it's wired through the P/N switch, I believe.
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Raydar
88 Formula IMSA Fastback. 4.9, NVG T550

Praise the Lowered!

[This message has been edited by Raydar (edited 07-13-2013).]

You guys are awesome!! Thanks so much!!!