How did everyone handle the wiring harness.......
Thread Starter
Junior Member
Joined: Nov 2003
Posts: 70
Likes: 0
From: Newport, NC
Car: 09 Honda Fit / 91 Camaro RS
How did everyone handle the wiring harness.......
Ive almost pulled mine all the way out. I would like to know if anyone has a FAQ or a walkthrough on what was pulled and reused. Im not worried too much about oil pressure and temp at the moment. I will take the harness out and apart to determine whats needed and what can be stripped out. Wanted to know if anyone has a FAQ or basics on what they did.
Thank you!
Thank you!
Member
Joined: Apr 2011
Posts: 381
Likes: 0
From: long island ny
Car: 1987 camaro sc
Engine: lg4 305
Transmission: 700r4
Axle/Gears: 2.73
Re: How did everyone handle the wiring harness.......
heres an article for swapping over to a carb https://www.thirdgen.org/carbswap should give the basics
Joined: Dec 2004
Posts: 2,042
Likes: 18
From: Lincolnton, NC
Car: 88 IROC
Engine: 97 5.7 Vortec LT4 hotcam
Transmission: 700 r4
Axle/Gears: 3.73
Re: How did everyone handle the wiring harness.......
just get the wiring diagrams for your car and CLEANLY remove what you dont need.
Senior Member
Joined: Sep 2004
Posts: 719
Likes: 0
From: N. Ky
Car: 86 T/A - 70 Z28/RS
Engine: Broke - 350
Transmission: 700R4 - M22
Axle/Gears: G80, 2.73 - ZQ9 G80 4.10
Re: How did everyone handle the wiring harness.......
There are two harnesses for your motor, An engine harness and an ECM harness. The engine harness will have the coolant temperature, ignition (+12V), Tach, A/C and oil pressure with it.
Go here for the correct wiring diagram for your car. Only thing that is missing on some of these schematics is the VSS cable for your speedo. You will have to do some cutting, splicing and add a ground to the VSS buffer board to get your speedo to work again.
Go here for the correct wiring diagram for your car. Only thing that is missing on some of these schematics is the VSS cable for your speedo. You will have to do some cutting, splicing and add a ground to the VSS buffer board to get your speedo to work again.
Thread Starter
Junior Member
Joined: Nov 2003
Posts: 70
Likes: 0
From: Newport, NC
Car: 09 Honda Fit / 91 Camaro RS
Re: How did everyone handle the wiring harness.......
I come from import world where harness tucks and that sort is the norm. I havent personally done one......so this will be fun. Best thing I can figure is pull harness......and yank whats not needed. Like you said. Didnt know if there was a DIY. Thank you!
Member
Joined: Sep 2007
Posts: 244
Likes: 0
From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: How did everyone handle the wiring harness.......
Just finished and tpi to carb swap and at first glance it looks good but if you snoop aroun the engine bay a little you'll find ends of wires taped off all over the place. I tried to bunch them together and hide them but if you have the time I'd pull the whole thing ad just leave what you need. My irocs my daily diver so I had to get it back on the road ASAP but eventually ill go back and do it right.
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Member
Joined: Sep 2007
Posts: 244
Likes: 0
From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: How did everyone handle the wiring harness.......
heres an article for swapping over to a carb https://www.thirdgen.org/carbswap should give the basics
Thread Starter
Junior Member
Joined: Nov 2003
Posts: 70
Likes: 0
From: Newport, NC
Car: 09 Honda Fit / 91 Camaro RS
Re: How did everyone handle the wiring harness.......
Its not lol....I was being courteous for the help being offered. OP was nice and tried to give me more than the "just search".
Senior Member

Joined: Feb 2008
Posts: 706
Likes: 0
From: Central PA
Car: 1990 IROC
Engine: Rebuilt L98 with H/C/I/Carb
Transmission: TH350 with ATI Treemaster
Axle/Gears: 7.5 with 4.10's
Re: How did everyone handle the wiring harness.......
I just finished "cleansing" my harness. Wait until you see the pile of wires and loom in the garbage when you are done!
Member
Joined: Sep 2007
Posts: 244
Likes: 0
From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Member
Joined: Sep 2007
Posts: 244
Likes: 0
From: central NJ
Car: 1988 iroc
Engine: 350 tpi
Transmission: t-5
Axle/Gears: stock
Re: How did everyone handle the wiring harness.......
You have any pics of the current harness? I could use the help. Does the fuel pump run off the ECM? I left my in tank pump in and added a regulator. Will it still prime and run with no ECM?
Senior Member

Joined: Feb 2008
Posts: 706
Likes: 0
From: Central PA
Car: 1990 IROC
Engine: Rebuilt L98 with H/C/I/Carb
Transmission: TH350 with ATI Treemaster
Axle/Gears: 7.5 with 4.10's
Re: How did everyone handle the wiring harness.......
I'll try to get a few pictures this weekend. There isn't much to see...just a bunch of bare wires for now. I bought new fabric loom and need to re-route everything. I haven't changed anything with the fuel pump (my ECM will still be there, just fewer wires coming out of it). I am not 100% sure about the fuel pump circuit. I think it needs key-on power, battery power, a ground and also a loop that runs through the oil pressure sensor. I haven't messed with any of that.
Joined: Dec 2004
Posts: 2,042
Likes: 18
From: Lincolnton, NC
Car: 88 IROC
Engine: 97 5.7 Vortec LT4 hotcam
Transmission: 700 r4
Axle/Gears: 3.73
Re: How did everyone handle the wiring harness.......
You dont have to have the ECM to run the fuel pump. I would have to look to be certain of all the details, but pancherj sounds right. I know I have mine through an oil pressure switch and I also wired in a spring toggle to use as a primer or so that I can adjust float levels easy.
I know my earlier post wasnt very helpfull, but some people really hack the wiring harness and makes the swap look terrible.
I know my earlier post wasnt very helpfull, but some people really hack the wiring harness and makes the swap look terrible.
Thread Starter
Junior Member
Joined: Nov 2003
Posts: 70
Likes: 0
From: Newport, NC
Car: 09 Honda Fit / 91 Camaro RS
Re: How did everyone handle the wiring harness.......
You dont have to have the ECM to run the fuel pump. I would have to look to be certain of all the details, but pancherj sounds right. I know I have mine through an oil pressure switch and I also wired in a spring toggle to use as a primer or so that I can adjust float levels easy.
I know my earlier post wasnt very helpfull, but some people really hack the wiring harness and makes the swap look terrible.
I know my earlier post wasnt very helpfull, but some people really hack the wiring harness and makes the swap look terrible.
Re: How did everyone handle the wiring harness.......
i swapped my 87 bird to carb a couple years ago and im just getting to cleaning up the harness here is a pic of what i have removed so far i am almost done with the passenger side of the engine bay.
the moral of the story is most of it becomes trash when you do a carb swap lol
the moral of the story is most of it becomes trash when you do a carb swap lol
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