The journey of 1000 miles starts with one step..

And boy was it a very intimidating step to take. Tonight we started and just about finished stripping my engine harness of all the useless plugs and wires and got a couple other things wired up right. For now my car is going to be running vacuum advance with a GM HEI module for an ignition, so we got that wired up. I still have a few things to do like finish taping up the harness and put loom on it, and then i'm gonna clean the crap out of it but already it looks way cleaner. I'm not worried about hiding anything because it's not a show car and i don't wanna make anything high maintenance...just getting rid of the non essentials really cleaned things up.

Here's a before shot...notice all the random crap behind the passenger strut tower, and the rotted out mess on the driver's side frame rail...that part used to be the main harness that went to the stock ignition, which is now long gone. The rest was all for emissions junk.





I didn't get a chance to take a pic of where it's at right now, but here's a few pics of the mess we got into







^^ This pic doesn't even hint at the horror that's under the dash. The biggest goal in this was to get rid of the dry rotted mess on the driver's side frame rail. We half expected that harness to simply plug up somewhere under the dash...boy were we wrong. In the end we had the entire wiring harness for the whole car unhooked.



^^ This pic is of the mess relating to the AC control ECU...or whatever the heck the ECU in an '85 is used for. There are a couple wires that we're not 100% sure are for but we think they go over to the HVAC for the AC controls.


Tomorrow i need to finish wrapping the harness and then put some loom on it, and i'm gonna have the alt tested just to make sure it's charging...i was pretty amazed that it fired right up after digging that deep into the harness, but really all that you see going across the firewall is headlights/alternator/coil wiring...only a single key on wire goes to the ignition to make the car run.

1990Coupe said:

Thats pretty intense! I give you credit, i can't dig that deep into a harness like that. I'd mess SOMETHING up im sure!

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I can't take all the credit...my buddy's an electrician and all around brainy guy and he did all the thinking work. It ended up being pretty straight forward....just take the junk from the engine bay that we're not using and trace it back to the plugs and eliminate it.

S&B said:

why is all the loom off your harness, its much easier if yo uleave all that on

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Because we were taking one wire at a time out of the harness, so that meant pulling wire at a time through the firewall, which is about impossible with a bunch of tape on it. We had hoped it would be as simple as unplugging the harness that went to the stock ignition, but there were a lot of wires that crisscrossed from one side to the other. Doing it one wire at a time ensured that we didn't cut out anything that we might have needed for something else.

Another thing we're not sure of is there's a white wire that had something to do with the alternator. A while back we installed a 3G in my car which is pretty tricky since my car originally ran an external regulator (again, my buddy did the thinking work for this one...i don't know jack about wiring). Anyways that white wire ended up going nowhere and we're not 100% sure that its charging right so today i'm gonna go and have it tested for good measure.

GT89Mustang said:

If it was originally a carb'ed car why is there so much extra wiring?

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Emissions is the majority of it, AC controls (where the ECU comes in), plus i think some of it may have been from when it was a police car. The stock ignition alone had its own harness with probably 20 wires in it. Then there's the external regulator for the alternator...that's more wiring. Amazingly it's still less than EFI, but when you break open the harness it looks worse than it is.

Actually it was fear of a fire that really pushed me to do it. Here's a closer shot at the mess on the driver's side i'm talking about




It's one of those things like a physical flaw that you hide about yourself and maybe nobody else really notices it but you know it's there and it eats you alive. Plus i've been kind of ashamed of it so when i take pics i'm careful to hide it as best as possible


Not only is it ugly and covered in oil but there were several naked wires in there. I don't know if any of them had power going to them or not but the insulation on the wires was all dry rotted and brittle and i figured it was a time bomb. Then on the passenger side there was like 8 plugs that didn't go to anything anymore, used to be emissions junk i guess. I REALLY wanted to get rid of this jumbled mess of fusable links under the coil, but i think they all go for the headlight harness on that side so it's best to leave those alone.

It's pouring rain out right now or i'd be out there taping up the harness and finishing it up for pics but i guess they'll have to wait. Like mentioned before it really is crazy how much wiring there is for a carbed car. With this GM ignition module i'm using, there's literally only 1 key on wire to make the car run. If it were a strip only race car without an alternator and head lights, the only wires would be to the ignition/coil/starter.

I got some taping done today and stuffed the wires where they'll eventually be but i haven't got loom yet. I still need to figure out how to tape up the wiring right up against the firewall...might have to unplug everything and pull the harness through as far as i can and tape it up that way. I also still haven't cleaned anything yet...you wouldn't believe how dirty this job was, it got dust/dirt/crud all over my engine and pretty much everywhere.

Here's the driver's side...this is my favorite part just because of the horror that used to be there (before i taped up the rest of it):



Here's a pic of the HEI ignition module, tucked back behind the passenger side strut tower. I need to paint the little bracket i made, but i'm looking for a computer heat sink to replace it anyways:



And here's an overall shot. I like how the harness tucks up under the firewall crimp:




Once it's loomed and cleaned and i tidy up a few other things, repaint my accessory brackets and i'd like to get new plug wires, i think it'll all look much much better.