Short in Air Conditioner Controller? Topic is solved

[Carbuff2]

Being cool in the summer is important to me. Call me decadent.

So, I insisted that the '94 940 Wagon I'm buying have working A/C. The present owner (a family member) said it doesn't work. I told him to have it diagnosed.

Here's what I was told: "The air conditioner controller has a short. My mechanic will take it apart and soldier/fix it for $125."


I perused some of the Volvo sites a while and never found any mention of such a problem. Is this a common problem on this vintage Volvo? If so, what is the fix, specifically?

What other common A/C system failures are likely?

Respectfully,

Atwell Haines
Soon-to-be-owner-of '94 940 Wagon
NJ

[LaRy]

It does exist some controller unit, according to the electrical drawings. This controller is taking car of the complete ECC function, so if the heating works this unit should hopefully also work for the AC.
I would try to find the over/under pressure switch placed somewhere in the system checking the "cooling media". If you have under pressure it should stop the AC compressor from starting. The AC compressor has one ground and one more wire, that wire is going to this pressure switch. Check the switch, it should be normally closed. Colour from compressor could be GN-R or GN-Y, the other side of the switch is also GN-Y. In Hanes repair manual you will find 1 page about the sensors, values and how to make some tests. Also Haynes is writing that if the controll unit is broken, you can not repair it.