My a/c blows cold while I'm driving,but at an idle it stops blowing cold air. Any suggestions? On my 98 1/2 24 valve 3500,automatic.

 

Does the fan keep blowing even though its not pushing cold air? If so, then it seems you have a blend door issue.

 

I also had this issue and it was my radiator was clogged in the cooling fins with cotton from a cooton wood tree and only were the fan and fan shroud meet the radiator clean it with air and a garden hose

 

Your system may need recharged. Possible leak?? Compresser kicking on?

 

Yes,it kicks on. It won't blow cold at an idle. Any suggestions?

 

Have you checked the blend doors? Have you checked the Freon levels?

 

It won't blow cold at an idle,but does fine while rpm's are up.

 

Make sure your serpentine belt is good/tight. AC compressor won't work if it's not turning fast enough.

 

The way I do things is try to look for the easy and cheap stuff to fix first. Like I said, recharge it and if that doesn't work try the belt as also said. If it's kicking on and off that can be a sign the pressure is low.

 

Is the truck warmed up when it's not blowing at idle? It seems like mine does that too.