My 94 / 850 Turbo with Dual Pasenger Control AC runs and cranks out cool air for a few minutes and the starts blowing hot air. Sometimes the passenger side vents are blowing hot while the driver side is blowing cold. Otehr times when I turn it on I get no cool air at all.

 

Is it manual climate control or electronic climate control?
Is the compressor still running when it blows warm?

 

Its has auto climate control setting. I believe the compressor is cutting out. The unit actually starts blowing HOT heated air even with the temp setting on max cool.

 

Low on freon......hope for a small leak otherwise get ready for replacing the cooling coil in the abyss of the dash board.

 

The clutch might need to be re shimmed.

 

What causes the clutch to need to be re shimmed. Do the shims become compress over time?

 

NO NO NO NO,

FIRST CHECK the freon level. Most likely you need to charge it BUT the other issue is probably the temperature sensors in the headliner areas.

Look at the "oh sh*t or grab handles above each window.

There is a small hole in a plastic cover. The hole is about 1/4" or so.

Blow some clean compressed air in there. one of the "computer blaster" cans with the red tube works well.

The reasons I say this are

1. Most people do not even know they are there.
2. He gets cold air on one side and not the other sometimes.
There is only ONE compressor so if it was bad or the clutch was slipping or he was low on freon, he would have the same temp air from BOTH sides of the vents. Not just one.

 

Both sides of the clutch wear over time. That's why it needs to be reshimmed.

 

I believe he has 2 issues here. I wanted to make sure he has a fully working A/C then work on the hot/cold out of the vents on each side.