mphsprelude

Ok, I have something I want to throw at you guys. And please correct me if you think I'm mistaken. I have had a LOT of prelude experience over the past almost 8 years. Not just mine but everyone else that has a problem. They all make their way to me eventually. Every time I diagnose a problem in these cars it's always, I mean always, electrical. A sensor or something has gone out. I have come to the conclusion that it isn't the sensors really at all. It's the wiring harnesses. I have now found that on three of the ludes I work on that the actual copper under the wires plastic coating is very oxidized. So I'm in the process of looking for new harnesses or just making them on my own with new wires. It's always been my experience that oxidation and electricity do not mix AT ALL.
The harnesses I'm mostly talking about are the two fender harnesses, engine harness, and the harness going to the fuse box and then into the car(<---- mainly the one going to the fuse box).

The first place i usually start looking is the grounds behind the headlights. Then i start feeling to see if the wire is stiff or loose. If it's stiff that usually means that its oxidized under the coating of the wire causing the electrical current to stop flowing. This causes the sensors to pulse. Which causes idle surges.

Please tell me what you think.

Tszyu1

Hey Memphis, Little Rock here. I would have to agree with you. My 97 SH is experiencing the infamous idle surge and 2k-3k hesitation. Drives me totally crazy! I am going to try disconnecting the tps (per rodhay's post) to check its functionality; I neither have nor know how to use a voltmeter.

Also, not completely o/t, my low beam headlights went out awhile back. I believe they expired at the same time, IIRC. I have checked the fuses and bulbs to no avail. Any suggestions?

Thanks, and keep us posted with your wiring adventures.

snobordboy

Aside from a headlight plug getting corroded, and the infamous main relay issue, all of the electrical problems on my car have been my doing. If I had not messed with my harness so many times, and tucked things differently than they came stock, I would not have had any problems.

That said, my 9 year newer Subaru has had wiring get oxidized or fall apart deep into harnesses, which has taken hours to get to, repair, and get back into place, even if I know exactly where to find the problem.