AC Issue

[ajoliver2010]

Long story short..ac blows hot on driver side (blend door was changed). Compressor works fine..ac drain is bone dry (tried coat hangar but no luck). Radiator fan only turns on when engine is hot. Ac low port reads 50 psi..high port reads 150 psi. Solutions??

[J57ltr]

Does it cool off when you are running down the road? The fans should run anytime the compressor is called for.

When you say the fan only runs when the engine is hot is it only the passenger side or both fans?

Try exchanging fan relay 2 or 3 for 1 and see if they turn on. Both should run when the AC is on.

[ajoliver2010]

Yes it cools off on the highway.Both fans turn on when the engine is hot. What about the ac drain being bone dry?

[J57ltr]

The fans not running while parked and AC on is an issue, and could cause it to be hot at idle. But I would expect the pressures to spike pretty high. The other thing is that the compressor may be stuck in low displacement, Most of the GM cars I have dealt with in the last 10 or more years have the CVC compressor which is a variable displacement compressor and will change displacement from high when first started to low displacement when it cools the car down thus no need to cycle the compressor. There is a valve that controls that in the switching that seems to get stuck in the low mode. This usually shows normal low side pressures but low high side pressures. You should be 45-240 or so depending on temp and when the car is nice and cool you will see the high side pressure drop to about 150. I had that happen on my 97 Park Ave. and it wouldn't produce much in the way of condensation at idle and our humidity is on the 60%-90% range here on the gulf coast. When I would get off the freeway and park then it would drain when I stopped. My options were to replace the valve in the compressor which requires removing the Freon and changing the valve or replacing the whole compressor.

I would figure out why your fans are not running first then see what happens then.

[NotEnoughGPs]

Following this with interest as my 40th anniversary is also throwing hot air on the drivers side vents, cold on passenger side. Fans are working. I will do a thorough check on the system. 235,000 miles and this is first issue with the air conditioning system. These cars are junk. Trading it in (just kidding)

[ajoliver2010]

I tried the relays but same result. I have a repair manual so I'll look into that and the compressor. And I can't trade my baby because she has no air lol. Rusty and everything, I love my gp!!!

[J57ltr]

Hmm, well ohm out each fan individually if one of the fans is open then neither fan will operate. The way they have 2 speeds is that on low both fans are tied in series so each one has half the voltage dropped across them. If one fan is open then neither will run, if 1 is shorted you have 1 fan run fast and the other not run at all. Something is keeping them from running.