Looking at another of the non-working secondary systems - the fresh air blower.

The blower motor itself works fine (after some oil on the bearing felt). I can jump it with 12v and it spins like crazy.

But I can't make it work with the switch on the vent panel. The fuse is good, and at the 4-post plug on the blower hosing, one is hot (12v), and each of the other 3 show a ground in one of the 3 switch speeds.

I've determined that the blower motor is seeing the 12v side, but nothing happens in any of the 3 speed positions, so I'm wondering if the resistor pack in these cars is a common problem. Is there any way to test this stuff?