curious a/c issue; have done basic diag already!

BerniniCaCO3 · Post by **BerniniCaCO3** » 20 Jul 2011, 19:39

Alright, odd issue on an '06 S40.
The a/c stopped working, looked up a wiring diagram, sure enough fuse #27 (iirc), 15amp, on the power side of the circuit, supplying the magnetic clutch, was blown. Replaced, 30 minutes of cold a/c later, blew warm and the fuse was blown again.

This time replaced the clutch, volvo part, did it the right way, shimmed to .4mm I think. .38 would go in, .5mm would not. So that should be fine an dandy.

A day or two later, crap, stops working again. Blown fuse again! I replace the fuse. A/C works again. I drive 8 miles, do a quick errand, get back to the car, and the a/c isn't working, again. But this time, when I cycle the a/c (just turn off the a/c button, then turn it on again), the a/c miraculously works again. This time it stopped working, but not because of a fuse.
I haven't been able to duplicate it a 2nd time this evening.

So presuming, and pretty safely I feel, that the new clutch is good and installed and shimmed correctly, what else would occasionally blow a fuse and also lead to the a/c spontaneously not working when I first started up the car again after that errand, but cycling the button corrected it?

There are NO codes that the dealer found, btw. I say that, as I know there are many codes that only a dealer would see... a $50 obdii scanner would just do generic engine faults and wouldn't cover an a/c issue anyway.

gherman · Post by **gherman** » 21 Jul 2011, 14:25

The dealer didn't know what was wrong either?

BerniniCaCO3 · Post by **BerniniCaCO3** » 21 Jul 2011, 17:39

nope! they're going to wait until the fuse blows again or the non-fuse-blowing symptom repeats itself again or hopefully several more times, so the condition is more clear.

The wiring diagram only shows the a/c magnetic clutch, but the fuse box cover for that fuse (it is #27, and it's 10amp, just checked again today), also says "wat. something something val." Err, the car isn't with me now, wish I remembered the something something. I think it was relief or control. What on earth could that be? Sound like water (i.e. coolant), but I thought that system was fully autonomous and analog, unless the thermostats are solenoid-operated these days! Just kidding. Can't think of any electric water something something valve, unless wat. and val. aren't water and aren't valve.