Questions and Answers

Burnt OPS Wires Q. Hi Vince, I've got a 1991 Buick Regal Custom, 3.8 liter V-6 engine, automatic transmission, 87,258 miles, fuel Injected, No ABS, P/S, A/C, & Cruise, Rack and Pinion Steering.

Here's the problem: The wiring harness from my oil pressure switch melted down and shorted out after coming in contact with the manifold so the car just died. (No signal from the oil pressure switch I was told will shut down the engine to protect it.) Okay, so I had it towed to a shop who repaired the harness and replaced the Oil pressure switch but still couldn't get the car started.

He said he wasn't getting a signal from the computer to the fuel pump (a grey wire) when the key was turned on so he bypassed the circuit by running a wire (Parallel) directly to the # 1 terminal on a relay in the electrical center on the passenger side fender. So when the key is turned to start there is 12 volts at the terminal and this has the vehicle starting and running fine.

So he says the computers probably bad. I went to my regular mechanic and ran the story by him verbally and he agreed. So I went out and bought a computer from a local Buick dealer for $189.00, put it in. Of course I disconnected the battery first, and followed the instructions for removal and replacement of the Mem/Cal module to the letter. I removed the bypass wire he ran to the relay I mentioned and Voila, it won't start. Why??? Can the Mem/Cal module be bad also? And if so how much does one of these cost? The car is currently not in use but I'm prepping it for use in Jan/Feb 2002.

Thanks for your help,
Dan

A. It would seem to me that the wire that was bypassed is still not making a connection from the OPS to the computer. If it ran with the bypass wire with the old computer, that tells me the wire, not the computer is bad.

I would go back and check that gray wire from switch to computer and I'll bet you fifty cents cold hard cash that there is another break in the wire.

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