My 1989 760T recently had the main fuel pump fail which caused it to blow the fuel pump fuse. I put out a message about that problem last week. It is at a garage where the fuel pump was replaced. Today the guy called and said the car runs fine, but some wiring under the dash is getting hot enough to smoke. No fuses are blowing. He is now trying to sort that out. He has the wiring diagrams and a person with Volvo experience to work on it. I'm wondering if anyone out there has any ideas on this problem. I have had the car a month and put 800 trouble free miles on it. I just took it in to have the AC repaired. I'd appreciate any ideas.

Alan

The 700 series is notorious for that kind of thing happening. I've seen a lot of burnouts because of stereo wiring overpowering circuits in the electronic system, and for example, other electrical issues causing hot wiring. The wire gauge is not sufficient for circuit loads in several cases.

One VERY likely potential is that the condenser fan has seized. I don't know if 1989 ran the condenser fan from the pressure switches in the condenser, or from the temperature sensor in the radiator. Either way, if the fan is seized, it CAN (I have seen this before) burn the wiring ALL THE WAY to the dashboard control unit.

I'm thinking either you have a ground backfeed from another circuit or there is a problem with that specific wiring cluster.
--
1992 940 wagon, 72k

Thanks for the info, I will check out that fan. However, my problem has been found. The oxygen sensor wire was shorted, possibly when I changed the oil filter (for the first time, I have only had the car for a month). I don't remember seeing the wire, but that apparently was the problem.
Alan

Wow, that's a new one.

The moral is, the 700 does have somewhat vulnerable wiring in the dashboard and fusebox. Some of it is good for the job intended, but has no hope of surviving a minor short or overload.
--
1992 940 wagon, 72k