My a/c in my 2003 Tahoe will not cool well at all at idle, acts like it's low on Freon but it's not. Soon as I start down the road it cools down ice cold but in town if you stop at a store and shut it off when you crank it back up if you're in stop and go traffic prepare to get hot! Start moving down the road and it's good! Driving me nuts! Anyone else had this problem? Thanks in advance!

 

Welcome to the forum.
The first thing I would do is check the fan function to make sure that it's turning on. I can't remember if that particular year is electric or belt driven. Either way since it cools sufficiently when highway speeds are driven, it sounds like maybe the fans are not coming on or not running fast enough. Another thing to check would be to make sure there's not a bunch of debris clogging the condenser and radiator.

 

+1 for checking fan operation
-another thing to try is; when stopped in park, and the ac has gone warm, rev the engine up to 2500 rpm and hold it there for 10 seconds. If the ac goes cold, either the refrigerant level is low or the compressor is old and tired.

 

It's a belt driven fan clutch, may be time to change it. Thanks!

 

I've tried that, doesn't seem to make a difference and the level is good, thinking it probably is the fan clutch. Thanks!

 

You can tell if it's the fan clutch by listening to it when it starts to heat up and see if revving the engine up increases the fan roar or not. If it doesn't then the fan clutch is probably bad.

 

Thanks, I'll try that!

 

if you have pressure gauges...monitor the pressures...with poor fan operation the low and high side pressures will be high. with no fan operation the high side cut out will shut down the system in minutes.