1995 940 AC Clutch not engaging

Post by **jimmy57** » 27 Mar 2015, 12:45

Another very common failure is in the circuit on the controls in dash. A copper element on the board burns through or the solder joint where the circuit board mounted relay cracks. Both are not too hard to repair.
If it is either of these issues then there will not be 12V at one of the terminals in the plug for the pressure cycling switch on accumulator.

GESY940 · Post by **GESY940** » 27 Mar 2015, 13:36

Thanks, but I do have the 12 volts at the Low Pressure Sensor ( Beer Can )
What I don't know is which one of the 3 connectors is the HP Sensor.
And how to "DISCONNECT" the plug if possible

93Regina · Post by **93Regina** » 27 Mar 2015, 20:04

GESY940 wrote:Thanks, but I do have the 12 volts at the Low Pressure Sensor ( Beer Can )

But, the low pressure switch on the Beer Can was not evaluated.

Remove electrical connector from Beer Can's connector and do an ohm test on that low pressure switch...does current flow thru it?

Post by **jimmy57** » 27 Mar 2015, 20:22

Two of the switches are for fan so jumper those will run the fan at low or high speed. That would leave the other as the excess high pressure cut-out switch that could interrupt power supply to compressor clutch if faulty or connections corroded. The switch connectors unplug if you depress the wire bail on the connector. The illustration shows "high pressure sensor" but that is not used on 940 models. It would be a single three wire sensor and not a set of three two wire switches.

93Regina · Post by **93Regina** » 27 Mar 2015, 20:54

GESY940 wrote:Regina, there are 3 connectors

Wire Color - GN-R

But, do the ohm check first on the low pressure switch.

GESY940 · Post by **GESY940** » 28 Mar 2015, 05:50

Thanks Jimmy but the picture shows EXACTLY how my car is, it does have the 3 connectors
however don't be surprise that previous owner change it before.
VERY GOOD INFO -----------> 1000 OF THANKS!
I think I saw / know, what you mean about the wire connector, each one have one.

GESY940 · Post by **GESY940** » 28 Mar 2015, 05:54

Thanks Jimmy, the picture shows EXACTLY how my car is.
( 1995 Volvo 940 Turbo wagon ) I would not be surprise is that
a exchange from previous owner,
10000000000000 of thanks EXELLENT INFO!

Post by **jimmy57** » 28 Mar 2015, 08:45

There is another illustration in Volvo literature with the three switches labeled as to function. That would be the EXACT one for your car.
My recollection is that there is a gray, violet, and yellow or tan switch and the grey and violet are fan and the yellow or tan is the high pressure compressor interrupt.

GESY940 · Post by **GESY940** » 28 Mar 2015, 13:33

If you talking about the sockets or connectors, one is gray, the other 2 pink.
I cant see the wiring because they are well protected.
On some place I read that the HP switch is the far left, but really that
can change at any time.....

Post by **jimmy57** » 28 Mar 2015, 14:55

I'm talking about the color of the switch bodies.
The connectors have slots that should keep the wrong connector from going on the wrong switch.
You will still not have an answer until you jumper the pins in the switch connectors to know which one does what. When you ID the two that run fan then the one remining is the compressor cut out. one of its pins would have 12V with engine running, a/c on and then the remaining one goes to compressor clutch. If you have 12V then jumper it to see if compressor kicks on. If it does then you need a high pressure cut-out switch.

1995 940 AC Clutch not engaging

Re: 1995 940 AC Clutch not engaging