We have a 2000 S70. After running for about 20 minutes the AC quits blowing cold air. I can hear the blending vents change (vacume). If you turn the AC off for a few, it starts to work again. This always happens during the day. At night when it is cooler, it runs fine.

Can anyone help?

 

I would say the compressor needs to be reshimmed.

 

Thanks, I will check. I found this.

https://volvoforums.com/m_34431/tm.htm

 

This is my wife's car so I do not drive it everyday. However I realized the cooling fan only runs on low when the ac is turned on.

I never hear it cycle on high when the water temp increases. After checking, the fan is working fine (high low) and the water temp sending unit seems ok.It must be the fan relay above the radiator.Ordered one for $79.00.

AC ref. is getting to warm causing high pressure, which shuts the ac off. This is what a coworker which does AC work on the side, aggrees it may be.

 

One more thing! If the relay does not do the trick. My next thought is the thermostate. I replaced it last winter. The guy at the parts store said it should not be a problem because it is a lower temperature thermostate then the factory.

If the water temp does not come up high enough, maybe it never triggers the cooling fanto high?

Any thoughts?

Bill

 

When it starts blowing warm check for power at the compressor. If you have power and the compressor isn't working the clutch needs reshimming.

 

The compressor is fine.

 

Then you have no power to the compressor when it starts blowing warm?

 

Yes. Then if I shut the air off for 5 to 10 minutes and turn it back on, it works again. Allowing it to cool down. Shuting it off must allow it to reset I guess. Because if I leave it on it will not cool again.If I keep going at freeway speeds 65 plus. It will not shut down. If I drive at night when it's cooler it will not shut down. If I drive city roads it shuts down much faster. By the way I am in Atlanta, it gets hot. According to the AC guy, there is a pressure switch that will triger. High temps equal higher pressure.

I know the cooling fan is not running on high. When the wife comes home the fan would run for maybe 5 minutes after turning the car off. I never hear it run now. I jumped the fan and it is fine. Sucker has a 30 amp breaker. The jumper wire I used got warm in about 10 seconds. Do you have any idea at what water temp the fan trips on?Auto parts store says factory thermostate was a 190Dthe one I put in is a 185D.I'm surprised I have not seen much of an over heating problem temp gauge stays at 3 oclock.

Oh yeah,
Yesterday the AC quit in the house, LOL. Lucky its under warranty and we have two units.

 

I would try a high pressure switch first.