i am dealing with a 2004 s80 with a 2.9 auto non turbo that was involved in a front end collision.when going to charge the a\c it would not allow the compresser to kick on.i took my power probe meter and energized the leads off of the high pressure switch and when i did the electric fans speed up rapidly and then the car stalled .i got back in the car and started it and the check engine light was on and the temp guage on the dash was not woking .i scanned the vehicle and it said the etc sesor imput was high .i took it to the volvo dealer in tallahassee they scanned it and said the etc and the pressure switch on ac compresser was bad.they replaced both items and it didnt fix the car yet they still charged me 700.oo now they said that they think it may be the wiring harness because the ground side to the etc is reading over 5 volts i think personally that it may be the ecm can anyone help with this??oh if the etc is hooked up you must un hook the high pressure switch from the ac or uplug the ecm cable ......

 

You might have shorted something when you used the probe to power it.