You´ve basically checked all the basics. Do you have a chance to get an ATE ABS unit to swap in? I know they are not supposed to fail, but then they are over 20 years old by now. My 95 had a similar issue that I never figured out. One thing: Have you checked the wiring loom that goes into the ABS un...

Don´t you have junkyards down under? Those modules are quite pricey, it´d be a shame to spend money on an unlikely part. Still very strange that it happened while being parked which would make me believe it was a rhodant (or another freak-creature), but then you should be able to find a broken wire...

Rob, I think you can try to use a non tracs module for testing purpose. I´m not sure about that, especially since I never had a pre 96 module off the car. but I think you could get it on there. Tracs will not work, of course, but the ABS unit should.

Rob, thanks for closing loop in this , it's helpful to the next Volvo sufferer...