My brother just bought a 98 S70 GLT and the compressor seized so Volvo put on a new one, new accumulator, and acc belt. Even with the A/C button showing off the air blows ice cold and the lines have condensation on them. I assume it's electrical, what should I check or replace? The bill for a new compressor was $1300 so I'd rather check stuff myself than take it to Volvo first. I also am assuming thts what caused the compressor to go bad, or at least faster than it should have. Usually I wouldn't worry too much but when it seizes you can't drive the car.

 

HMM that is very weird.
You will have to trace it back to the Module in the Dash.(A/C controls)
Never seen that before. The Low pressure sensor wire must be getting power from somewhere.

 

Are most of the electronics in the A/C switches? I thought about replacing it but didn't know how much was in the controls and how much was located elsewhere.

 

There is 2 switches in the system. But they all receive signal from the Controls.
There is a high pressure switch and a Low pressure switch.

Do you have ECC or MCC?
ECC has AUT by the switches and ***** also have Temp in Numbers.
MCC just has speeds in Numbers and Temp in colors.

 

It has ECC. So would you recommend I replace the switches first or the controls? Thanks.

 

ECC the switches are part of the Control module.
Expensive to replace.
Do you have a wiring Diagram of your car?

 

I'll check, I have a Haynes manual and one on CD. I think the Haynes has wiring diagrams. I have a 98 V70 so I could trade them out just to troubleshoot.

 

If not look at the Link.
http://www.volvotechinfo.com/WD123/