ray green

iTrader: (14)

I have an 83 GSL with some wiring under the hood that has seen better days, although all systems still seem to work.

I also have two or three complete wiring harness sets from 84/85 GSLs. I could swap one of these in after I paint the engine bay if its compatible.

My head spins when I look at wiring diagrams and I don't have an intact 84/85 GSL in the yard right now for comparison, but as I recall there are significant differences.

Does anybody have any experience with this?

Thanks
Ray

82transam

iTrader: (18)

Ray - it could be made to work, but there are quite a few differences. The 83 only has one pass through hole in the firewall, on teh driver side. Everything, including the emissions control wiring etc goes through there. The 83 engines computer is on the driver side kick panel area, above the speaker whereas the 84/85 all have that computer in the passenger footwell, like the SE's.

In order to get an 84/85 wiring harness to work in an 83 you'd need to either rework the whole thing (too much effort, might as well repair the 83's at that point) or cut another hole in the firewall to pass the engine wiring through. That's not taking into account the differences in HVAC, gauges, switch location differences etc

If the 83's harness is that bad, it would be easier to find a replacement 83 harness in my opinion.

ray green

iTrader: (14)

That's the information I needed Sean, thank you very much!

I agree with your assessment, adapting the 84/85 harness would be way too much work.

In fact, even replacing the harness with one in better shape isn't a very good idea if the one you already have installed is salvageable.

I learned this yesterday when I set out to remove the harness from the 83 to paint the engine bay and lay the harness out on the lawn to compare with the 84/85 harness.

Disconnecting everything from under the hood was no problem, but when you get on the cabin side of the firewall it's a whole 'nother story.

Even with my dash already removed I quickly realized it would take a day or two just to extract the thing, and then I might never get it back together correctly.

So I'm just going to scoot the harness under the hood out of the way to paint the engine bay, then trouble shoot and repair any bad spots once the car is back together.

With everything in working order, a finish coat of black plastic electrical tape should make it look and work as good as new.

Thank for the help!

82transam

iTrader: (18)

Yeah the harnesses on these cars, even the simpler 83 and older versions, are more complicated than they need to be. Part of that is due to technology limitations back in the day of course (specifically the large box that controls the blinkers, and the engine's "ECU"), but the routing of it in general seems kinda silly. I've removed several of them for my restorations, and I always scratch my head as to why they decided to run a leg of the harness above the pedal box, basically sandwhiched between it and the firewall/cowl. Having to remove the pedals to get that section of harness out is just annoying...

For my current build, my 83 S/T2, I'm copying 82streetracer and installing a brand new GM style wiring harness. It'll take some work to get it adapted to the FB, but in the end it'll be a much cleaner and simpler setup.

Oh and if you need any specific connectors/wires let me know, I actually have a spare 83 wiring harness. It's not in very good shape, but it's not all bad - might have what you need.

ray green

iTrader: (14)

It was that bundle running over the pedal box that changed my mind about removing the harness, I suppose removing the pedal box would be a good idea but too much work if you don't really have to do it.

Thanks for the info and the help with those broken connectors when I find them Sean!

82transam

iTrader: (18)

You're welcome, just let me know! Yeah that harness is a pain to remove if you have a bad back, or are 6'-3", mildly overweight and generally awkward like me lol. Car yoga is definitely required to get in there to work!