2002 4.7L Auto, No Mods.....yet. This just started yesterday. Nothing has changed or been done to the truck, other than my normal everyday driving. At idle the AC blows warm, as if only the vent was blowing. Once I get going it cools off to the normal cold AC temp. Also it seems to be running warmer than usual. Nothing alarming in running temp, but just higher than usual. Any ideas would be helpful. I know we are close to fall, but I'm in So. Cal. and you may need the AC even in the dead of winter here. Thanks all.

 

could be low levels in the ac system, and the extra air going over the condenser while driving may overcome that problem. You might also want to check your AC pulley and clutch, to see if they are operating correctly while idling.

 

Not sure about your truck, but if you have a condensor radiator and fan, check that the fan is running.

 

Also check the fuses under the hood, mine was doing that too and I found I had a fuse that was blown for the ac, not sure which one, replaced it and the ac was colder at idle. I dont know why though.

 

Do a search, you shouldnt even have to go 2 pages into this section and will find the exact same question....

 

Just had the same problem on my '02 with 4.7L and no mods. Thought was the low pressure transducer, replaced still no go. Was told it was the ac condensor fan, replaced it. Still no go, fan not running running. Found a blown fuse for the ac condensor fan. Maybe bad fan blew it?? Maybe problem all along?? Live and learn.
Marty

 

Yeah.
You must make sure the AC conderser fan is running.
Switch on your truck, then the AC, then put the AC on defrost with max on the blower.
Your AC fan should come on instantly.
If not...... first check the fuse then work your way to the relay then check out the fan.
Just had this on my tuck.
I had to rebuild the AC condenserfan motor.
It all now runs sweet.
Al.