My 850 Turbo (110,000 miles) seems to be operating strange. The A/C works fine, when I accelerate hard the compresser shuts off like its supposed to ( I assume its supposed to anyway), but then it never comes back on. If I shut the A/C switch off for 2 minutes it comes back on and works fine. I've never had it turn off without accelerating hard. Is there a relay or something that controls this? Any ideas where to look?

Thanks in advance.
Brian

 

The clutch gap is way to big.

Either you need to install a new compressor or find someone that will be willing to remove it and reshim it.

 

You can visuallycheck if the compressor clutch works or not. Get somebody to help you. Turn the engine off, open the hood, leave the doors open. Put key in accessory position so the A/C works. Put the ECC air direction in the front position, fan speed in the middle, temperature in minimum (max cold). Now if you toggle the A/C on/offswitch you should be able to see and hear the compressor clutch engaging-disengaging.. If it doesn´t work tap it with a broomstick. If the broomstick moves the clutch then it has to be reshimmed.

I had to reshim mine, and that solved the compressor problem, but itstill cycles likes crazy. I suspect I have an evaporator leak, but since it´s been 0ºC this week here I am not very worried.

 

Thanks. I'll check the clutch. Why would the clutch work, but then not re-engage? This only happens when it shuts off becuase I'm stepping hard on the gas when taking off. Normal acceleration doesnt bother it.

 

I understand that the compressor clutch disengages when you floor the throttle. It is designed that way, maybe it is because the compressor takes somes power from the engine and you want the power if you want to accelerate really fast. I don´t know, I´m just guessing.

When the clutch isn´t working correctly it will fail randomly or suddenly disengage and not reengage any more until it cools down after a while. At last that´s what it did in my car.

 

I'll check the clutch this week, thanks for the advice.

I was curious if the A/C is working up to par so sitting in the drive with the A/C ***** at max (60Degrees) the air coming out the vent to the left of the steering wheel (which I would think would be the warmest) was about 67F while the outside air was 94F. Seems pretty good to me - For some reason Ialwaysthought a 20 degree difference was considered decent.

 

The clutch gets hot from the heat the gap expands even more and the magnetic field cannot hold the clutch anymore. Thats why it kicks off.