Hello All:

I have an electrical puzzle-- this AM my very pregnant wife came to me complaining that the newly refreshed AC wasn't working-- the blue light on the rocker switch wasn't coming on and it blew warm air...

I went outside and had a look-- my first thought was a fuse. I inspected all fuses visually then rotated and cleaned all of them. Still no go. I checked the light bulb in the switch itself-- it was fine. I tried jumping the low pressure switch on the AC-- the compressor did not run.

I started thinking about what other things might be on the circuits that make the AC run. The rear foglight switch would not light, and neither did the lamp in the taillight.

At this point I got a test light out and started looking for voltage at the lefthand and righthand sides of each fuse with the car running, starting from the top and working my way down. To my surprise, the bottom three fuses had no voltages on either side.

I was very puzzled by this, and started to look around for things that were different from the last time I drove the car. I noticed that the headlight switch, which I had just replaced two weeks ago, was switched off (I leave the lights on all the time). When I turned it on, the AC and rear foglamp came to life!

What gives? Is the headlamp switch defective? It is an MTC part from FCPgroton.com (a great place for parts, BTW)... I think I tossed the old Volvo original part last week (the lights wouldn't go off in any switch position anymore) so I can't use that to diagnose it.

Any ideas?

--
Herb Goltz, London, Ontario, Canada '92 245 w/102K mi