1997 850 glt me4.4 ac compressor won't come on

[tryingbe]

Shouldn't a 97 have a M4.3 ECU?

[abscate]

Fix that clutch gap number one. Closing that big gap is pulling the springs twice as far so they pull the clutch off with twice the force. Get it on the Low side with zip ties

[Ozark Lee]

Some '97s have a 4.4 and some have a 4.3. As far as the A/C goes it doesn't matter. The ME7 is the one where everything changes and the compressor is directly controlled by the ECU rather than the relay.

Do you have battery voltage on the Blue/Gray pin on the low pressure switch connector when the A/C is turned on? If not you may have a bad A/C relay. The relay is back behind/under the glove box.

The codes really don't tell you anything about compressor engagement problems anyway, they deal with controller and blower problems but not compressor related problems.

...Lee

[erikv11]

Any P80 car with an air pump, NA or turbo, is m4.4. Lots of air pumps in 97.
http://new.volvocars.com/ownersdocs/199 ... n1997.html

Is there r134a pressure in the system now, or did it all leak out?

[Ozark Lee]

friend pointed me toward the compressor thermal cutout switch...
can those be replaced without evacuating the ac and or does the pump have to be replaced instead?

You can just bypass it directly without removing the compressor.

...Lee

[tryingbe]

Nope, the thermal switch is only bolt to the outside of the a/c compressor housing.