[GMAN70]

OK Guys need some help, My wife's Volvo A/C has issues, Blows cold then turns hot. the outside temp today is 73 degrees, with the A/C on it is running at 45 psi, blowing 40 degrees inside. The compressor doesn't cycle until I pull the relay. With the relay out, psi goes up to 70 and blows 75 degrees inside the car. All fuses are good. I'm thinking the relay is bad, or what controls the relay? Thanks for any help!!

G

[cnc]

Just to clarify the system seems to work fine then all of a sudden it seems to gets hot and wont get cold again till you pull the relay correct....or possible shut the car off and cool down ???

If it comes on ( clutch engaged ) then shuts off ( clutch Disengaged ) and it seems to happen when the car is hot city driving for example ....
Do this ( A/C switched on car running be very careful of the Serpentine belt dont want to lose any fingers ) Check for power at the bullet connector (white connector disconnected u can disconnect before starting the car ) located on the side of the compessor...if there is power at the bullet connector plug ( car harness side ) plug the connector back in if the Compressor doesn't come on the compressor is done The A/c System is controlled via a relay, a shunt and a low press switch also the ECM controls the ground ...
Best thing that can happen is turn the A/C on and monitor the clutch make sure it engaged then watch to see if/when it disengages then check the bullet connector for power

Basically if you have power at the bullet connector and the compressor doesn't come on you need a compressor...( on a known good system ) let me know ...Chris

[Dr. Drivability]

Based on the limited info given, sounds like you may have a bad low pressure switch. That controls the compressor cycling on and off...is that what you meant by "relay" or is the temp control going hot by itself...need more info. Automatice or manual climate control? When/what was messed with last?

[cnc]

Jeff
I've never seen a low pressue switch engage the clutch then disengage when it got hot ( ambient temp) as this is what seems to be happening but maybe were mis-interperting what is goin on here ....and there is always a first time for everything as I'm sure your aware of fixin cars............lol.........Chris

[Dr. Drivability]

Like I said Chris, "limited info" with no car in front of me = best guess???. If it's automatic climate control, I'd be willing to bet the A/C amp/module is the culprit or possibly the sun sensor or ambient temp sensor.

[cnc]

Originally Posted by Dr. Drivability

Like I said Chris, "limited info" with no car in front of me = best guess???. If it's automatic climate control, I'd be willing to bet the A/C amp/module is the culprit or possibly the sun sensor or ambient temp sensor.

True enough Jeff...lets see what he comes back with.....

[Dr. Drivability]

He'll come back...when he gets hot enough

[cnc]

Originally Posted by Dr. Drivability

He'll come back...when he gets hot enough

LOL that was good....

[bastard]

http://www.brickboard.com/AWD/?model=S70
Best Volvo forum I found back when I had one.

[GMAN70]

Thanks guys, I do appreciate the help just been way too busy to look at her car or respond, two teenagers, hope to get a chance to get back to it this weekend. I will let you know how I make out!! Thank you very very much for your time!!

G

[T A 70]

Where's Bjorn when you need him...

[Old Blue 66]

Originally Posted by T A 70

Where's Bjorn when you need him...

Hes got the same car I think.

[T A 70]

Just asked him...he doesn't know....me either....good luck

[bastard]

I just noticed I had the wrong model on my link earlier.
http://www.brickboard.com/AWD/index.htm?model=V70