Engine bay harness

[Rocket350olds]

I have a 86 cutlass supreme and about a year ago I replaced the olds 307with a olds 355 and I would like to clean up the engine harness I want to keep the a/c, and cruise control if possible and the couple wires required to make the engine run and i would like to get rid of everything else not sure if their are instructions somewhere to do this

 

[buick7332]

I have a 86 cutlass supreme and about a year ago I replaced the olds 307with a olds 355 and I would like to clean up the engine harness I want to keep the a/c, and cruise control if possible and the couple wires required to make the engine run and i would like to get rid of everything else not sure if their are instructions somewhere to do this View attachment 187015

The ecm harness runs through the bottom of the firewall on the passenger side. You can remove the whole thing. Pull your carpet back to find it. It's held in with a rubber grommet. I carefully cut the grommet out with a razor knife , unplugged the harness, and pulled it out. You will need to remove the check engine bulb. Don't remove the vacuum lines.

 

[mikester]

I did this in both of my Malibus. I have no idea what the Olds harnesses are like compared to Chevy but theres not a lot of circuits once you cut out the ECM wires.
I started by laying out all the wires on a piece of cardboard on top of the motor. Marked out what each one was for and what could have been deleted.
I wrote down all the different colors of the wire I needed. You can order small lengths of the different colors you need and the correct AWG to match the OEM wires from wirebarn.com. They had every color/size that I needed.
I ran the wires back to the bulkhead connection. From what Ive read it seems like the newer G bodies have different terminals in the bulkhead than the terminals in both my 81 and 83 but Im sure guys on the forum can point you in the right direction as far as where to buy them.
I also replaced the fusible link wires that go to the starter. Again, I dont know if your Olds has them but it was easy to do.
I have all Autometer electrical gauges so I didnt worry about the factory senders. They got cut out too and the wires to the gauges were on their own. The biggest issue with my harness was I put a crate motor with the serpentine setup so the AC and charging wires had to be switched to the opposite sides.
I hate doing wiring so for me it was a pain but it came out all right and it seems everything works. LOL

 

[Rocket350olds]

So I started disassembling the harness and I found that the transmission wires for my 200c are going through that harness so I assume ill have to remove all the wires but those

 

[pagrunt]

So I started disassembling the harness and I found that the transmission wires for my 200c are going through that harness so I assume ill have to remove all the wires but those

You'll need either a aftermarket or junk yard found non-computer lock up set up since the O.E. computer ties in the lock up function in with other sensors to contol the lock up function.

 

[Rocket350olds]

Do you know of any good kits out there I prefer a easy install kit and I plan on switching it with a 2004r trans sometime soon also