Hi all. We have a '92 Volvo 940 wagon, my wife has mentioned that the power windows have on odd ocassion failed to work over the past few months, but it always "fixed" itself just a few minutes later. This morning, however, all control failed from the driver's side (we did toggle the child-safety switch too, but all four windows failed to go up or down no matter what), yet the passenger side switch continued to work fine. During my poking around this evening, I found the passenger door control fails now too. The fuse is fine; the relay is shared with the fan, and the fan works fine. I've removed the switch block from the driver side, and the switches themselves are fine (and it would be difficult to explain how all switches failed simulataneously anyway if the problem was the actual switch assembly).
I'm now at a loss for what else could be wrong. Must I pull the whole door panel off and find the ground point? I can't work out what else might be both intermittent (historically) and so systemic. Does anybody have any other ideas?