I have a 1989 Volvo 240 with 185,000 miles. The voltage meter in the alternator failed and I had it replaced at the local alternator/starter repair shop. I suspect that the original alternator had already been replaced by a refurbished alternator. I neglected to label the wires when I removed them from the alternator and am baffled by the four (yes, four) wires that are dangling in the vicinity of the alternator. I am pretty sure that I got the B+ and D+ wires right. There is also a black wire with a funky connector that came of the ground post when I removed the alternator. I am positive that this wire has been put back where I took it from. The mysterious fourth wire is a blue wire, approximately the same gauge as the big red wire on top, also with a ring connector. It is not the oil pressure sensor wire. I put the mystery wire on the ground post of the alternator when I installed it, as it seemed like the most likely spot (not for any electrical reason, but because the wire seemed to want to go there). The car ran once, like a charm (it did not before, which leads me to think that the alternator was, in some sense, functioning). However, the next time I went to start the car, the battery was dead as a doornail, and perhaps coincidentally, perhaps not, I discovered that my fuel pump relay was shot (I recently replaced the intank fuel pump as well). I also might have just left the dome light on. Who knows?

Any suggestions? I am trying desperately to resurect this car without paying a mechinic and think that I am close. I think many problems would be solved if I knew where this fourth wire goes. Thanks for having the patience to read this winding description of a problem from a novice tinkerer.