LS7 Swap wiring question
Thread Starter
Supporting Vendor
Joined: Sep 2013
Posts: 3,099
Likes: 1,270
From: Harbor City California
LS7 Swap wiring question
1981 C3 corvette
Manual trans car
We are doing a Gen 4 442ci LS7 swap with stock c6z06 PCM, intake, TB
Question is can I delete this wiring harness from the car all together since we are going to be running an LS engine with E38 PCM
The wiring harness in question used to connect to the GM 1981 ECM that was located in the behind driver seat storage compartment and runs all the way to the engine bay (its the harness with the green tape at the end):
From the connection at the old ECM (in the driver side storage tray) there is only one other connector in that harness before it gets into the engine bay and it is this connector:
Does anyone know what that connector is for? HVAC?
If its HVAC im running a new Vintage air HVAC with electronic controller
We are replacing all the old wiring inside the car and if I dont need to buy the harness and can delete it without any issues I would prefer to do that.
https://americanheritageperformance.com/
Manual trans car
We are doing a Gen 4 442ci LS7 swap with stock c6z06 PCM, intake, TB
Question is can I delete this wiring harness from the car all together since we are going to be running an LS engine with E38 PCM
The wiring harness in question used to connect to the GM 1981 ECM that was located in the behind driver seat storage compartment and runs all the way to the engine bay (its the harness with the green tape at the end):
From the connection at the old ECM (in the driver side storage tray) there is only one other connector in that harness before it gets into the engine bay and it is this connector:
Does anyone know what that connector is for? HVAC?
If its HVAC im running a new Vintage air HVAC with electronic controller
We are replacing all the old wiring inside the car and if I dont need to buy the harness and can delete it without any issues I would prefer to do that.
https://americanheritageperformance.com/
Last edited by American Heritage; Aug 20, 2020 at 09:47 PM.
Burning Brakes
Joined: Aug 2016
Posts: 1,000
Likes: 283
From: New York
Anything for the old ECM can be deleted. If you are installing a new body harness depending on what you get you shouldn't need anything. I installed a universal harness so I still needed to reuse some of the connectors.
Last edited by nyciti; Aug 21, 2020 at 08:21 PM.
Thread Starter
Supporting Vendor
Joined: Sep 2013
Posts: 3,099
Likes: 1,270
From: Harbor City California
That is the info I needed.
https://americanheritageperformance.com/
Thread Starter
Supporting Vendor
Joined: Sep 2013
Posts: 3,099
Likes: 1,270
From: Harbor City California
Melting Slicks
Joined: Sep 2010
Posts: 3,310
Likes: 697
I don't really know how the ecm of that year were wired but it might be nice if they had a 12 volt constant wire and 12 volt in start and run wire (two separate wires) that you could use for the LS ecm.. Delete all the other wires.
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Instructor
Joined: Aug 2007
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From: New Bern NC
1981 Computer harness
I need the under the hood harness that hooks up to the original carburator. It plugs into the Compouer harness form the ECM. It is attached by two 6 pin connectore and goes to carburator, temperature sensor and emissions.
If this is available, I'm interested!
If this is available, I'm interested!
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,597
Likes: 7,046
From: New Or-leens Loo-z-anna
Keep labeling and taking pics of EVERY connection. Coil them up in neat bundles and tuck them out of the way until you get some miles on your car. You'd be surprised at how many of the original wires can be re-used with new connectors, which will save you the trouble of re-running wires through the firewall and into existing bundles behind the dash. Re-purposing original wires will also help you when you draw new wiring diagrams for your new/modified wiring.
Weeks from now all those original wiring pics and updated wiring pics will remind you of "Where the Red/green wire comes from under the dash and Why is it coiled up and zip-tied to the firewall?"
