A/C troubles

[whitetrash]

So when I start my truck my a/c will work great for about 10-20 min. Then it stops blowing cold. Any ideas?

[JimD]

When it quits cooling does the compressor cycle off and any lines have frost on them?

[whitetrash]

When it quits cooling does the compressor cycle off and any lines have frost on them?

I have it running in my driveway now to check. I'll let you know

[stephen4785]

Probably low on freon causing the evaporator to freeze up. Without looking at it I would guess to check for leaks and recharge.

[whitetrash]

i just let it run for 30 min with the hood up and it never quit. can underhood heat cause it to stop?

[stephen4785]

i just let it run for 30 min with the hood up and it never quit. can underhood heat cause it to stop?

Not unless it gets hot enough to catch something on fire.

[Reefer Rae]

Its freezing up due to being low , it won't freeze because the engine is at idle and isn't drawing the low side down really low . At 2000 rpm the low side is at crazy low pressures and freezes the evaporator . Add a can get the low side up to 40 ish psi at idle and the high side around 225 when its 90 degrees out. Look for a oily spot ( indicates a leak ) what kinda car?

[whitetrash]

2000 gmc Sierra. 5.3

[projectPONY]

Won't the high pressure switch cut the compressor if under hood temps are too high? My guess is that it will, that's why compressor didn't cycle off with hood up.


sent from an htc EVO, the iCrap killer.

[Reefer Rae]

Most likely the compressor is leaking . Look for oily residue on it . It's a common failure .