I've had my 1996 960 for a few months. It developed an issue with the a/c system. I was cruising along and it went from blowing cold to full on heat. Shortly after, found when i accelerated the fan slowed down to a low speed from high. As soon as I let off the pedal at speed, it sped back up. a few miles down the road it started blowinc ice cold. Any ideas on whats causing this to happen?

Hi,

Open the Bonnet and watch the A/C compressor clutch when the engine is in idle.
Then rev up the engine while looking on the compressor clutch to see if it disengages.

The vents are controlled by vacuum "pots" that die an early death in hot climates. The rubber seals rot out and you lose vacuum pressure. So when you accelerate and manifold vacuum drops there isn't enough pressure to keep the gates flipped the way you think you have them set and you aren't getting cold air from the a/c. It's expensive to fix. The receipts I got when I bought my car show that the previous owner paid $1100 to get those replaced about three years ago and mine are already going out again in the lovely South Carolina subtropics. Be glad your a/c starts blowing cold again. Mine just quits when the temperature gets much over 90 and no one has been able to figure out why. Already bypassed the gizmo on the side of the compressor, replaced the radiator to keep the engine running cooler, had the system pressure checked and charged up with fresh oil and 134a. It's just a Volvo quirk. The compressor stops kicking in for a random period of time and then starts working again whenever it feels like it. In under 90 degree weather it runs like a champ all the time. The previous owner spent $5k chasing the problem over a period of about 4 yrs, replaced every component in the system, and then gave up and sold the car.

ppcgm- After all the work you have done, you might try one more thing. There are three pressure switches at the condensor, you will need to unclip the grill to see them. One is a low pressure switch, which turns off the compressor when there is too little coolant in the system. One is a high pressure switch that turns the radiator fan on, usually under normal driving conditions. The last on is a high pressure switch that turn the compressor off, this is when there is danger of blowing out a hose. That is the one you should look at, you could try jumping is with a wire and see if that does it. Good luck.

DanR '94 964 336,000 miles (102,000 on the new engine)

Do you mean that the switch could be bad and needs to be replaced? I was told that there could be a ristriction in the system and I should try to replace the orifice tube and see if that helps. I bough the tube for $2 and i'm waiting on Oring set before i try it. Does any1 know where the tube is located on the 95 960? and by the way, I'm sure most of you know that when you push the recycling button on in any car you should get cooler air and more pressure coming out of the vents and you won't get the outside smell inside the car. This is my 2nd Volvo that this button doesn't do anything and you still smell the outside. I found foam in the vents when I bought this car, could this be the problem?

Thanks,

Jerry