Total electrical rework

[embalmer41]

Hello everyone. I was looking at my engine wiring harness and i know i can remove the engine wiring harness that connects to the fuel injectors, coolant sensors, etc. But is it possible to replace the entire underhood wiring harnesses. I have an electrical problem and i know it's in the harness because i've already found one short in it. I've noticed the wiring is brittle and cracking and i was thinking of going to the salvage yard and see if i could get a complete harness from the exact same car as mine. I was thinking of just replacing the whole underhood wiring because they all look suspicious. Is it possible to remove the entire wiring system from the engine compartment to another car of the exact same make.? It sounds like a lot of work, but i've put a new rebuilt engine in the vehicle, had the transmission reworked, and i wanted to redo wiring and everything. It's a 1989 Oldsmobile Cutlass Supreme, 2.8L and the bod and interior are in mint condition. I've had three offers to buy it, but i'm not selling. Any thoughts would be greatly appreciated.

[Robby1870]

Yeah, that's exactly what you should do. Go to a yard, get a wiring harness from a 2.8L auto W-car, and just swap them. Pretty straight forward.

[slick]

Plan to spend a solid weekend doing it.

[GIANT MOTH]

I consider electrical problems the number one problem in used vehicles. All I can say is that if you replace the wire harness from the junkyard your bound to get the same results from another brittle aged wire harness. If you know the problem is in the fuel injector harness why not be inventive? Recreate the wheel. There are all kinds of things you can do with wiring. You just have to master the connection.

[Supreme Cutlass]

If you know the problem is in the fuel injector harness why not be inventive? Recreate the wheel.

..Recreating the wheel is a bad thing ..

 

Just get a j/y one but test it first, make sure there aren't any broken wires or shorts so you don't end up with the same problem. Just to be proactive; if you're good with soldering, wiring and all that, re-wire some of the connections (especially the ones suject to the most road debris and heat, etc.) with good wire, solder and heavy duty heat heatshrink.

[slick]

Once you get a JY harness, i'd pull the wire loom apart(by section) and clean it with some strong degreaser and a brush. Afterwards, clean it with water. Be sure to have each connection completely dry and use di-electric grease liberally.

[1990lumina]

didn't 5speedz34 do this to his cutlass as well??

[slick]

didn't 5speedz34 do this to his cutlass as well??

 

Was going to, but ended up parting it out.

[Crazy K]

fortuneatly, I have both of tony's harnesses to do the 5 speed swap.

 

 

 

whether you get a j/y harness or not, you could do the same thing and remove your cars own harness to clean, degrease, and inspect.

 

truely... does it have to be a 89 CS only, or.... any 2.8 or 3.1 with the same connectors for instance? IIRC the egr connector get added to later hernesses, but no mush else changes until 93 when the Electrontic transmission is added.

 

(can any 89-92 2.8 or 3.1 harness work?)

[slick]

Well, with certain years, they had certain things(map vs. maf), but like 91-94, you can use the same harness for a 3.1 or a 3.4. You would just have to pull the loom apart and move some of the electrical connections around, then loom it back up.

[ns87]

Hey Embalmer where are you from? The only thing I've ever heard about my car is "How OLD is this thing???"

Anyway, I think the wiring harness unpluggs on the passenger side fender under the black plastic cover, near where the Engine Computer is. Wbody community, harass me if I'm wrong

 

[slick]

Hey Embalmer where are you from? The only thing I've ever heard about my car is "How OLD is this thing???"

Anyway, I think the wiring harness unpluggs on the passenger side fender under the black plastic cover, near where the Engine Computer is. Wbody community, harass me if I'm wrong

 

 

Ok, your wrong. The main harness unplugs at the firewall on the passener side, with a torx bit in the middle. I forget the exact size though.