A/C cold at idle warm while driving!

[ACerf]

Freon is good, tests fine and cools
Great at idle. Get out on the road it doesn't
Cool. Even at Max Air I get very little air, cold or
Otherwise. But after awhile it will get cold and good air flow.
Driver Side is always cold.

 

[6speed]

Sounds like it might be freezing up. Once on the road and it quits pushing air out the vents, pull over and open the hood and see if it had ice on the dryer and the lines around it.

 

[TJJEEPER]

Sounds like it might be the clutch. Had this problem on a car one time. Clutch holds just fine at idle but slips when the revs go up, heats up and then gets worse. It finally died on a trip between Bakersfield and Needles Ca in the middle of summer... not a fun drive!

Two opinions now!

 

[PWong]

Sounds like it might be the clutch. Had this problem on a car one time. Clutch holds just fine at idle but slips when the revs go up, heats up and then gets worse. It finally died on a trip between Bakersfield and Needles Ca in the middle of summer... not a fun drive!

Two opinions now!

I am going to say: Clutch operation wouldn't affect the air flow rate.

 

[PWong]

Freon is good, tests fine and cools
Great at idle. Get out on the road it doesn't
Cool. Even at Max Air I get very little air, cold or
Otherwise. But after awhile it will get cold and good air flow.
Driver Side is always cold.

According to the info you posted your system was low on refrigerant charge. Part of evaporator was frozen.
Hood up the manifold gauges to see high side and low side pressure for further diagnostic.

 

[B.G. Smith]

I would say you have blend door problems. With truck parked and running try switching between AC, Max AC, defrost etc and see if the air flow switches to the modes selected? bg

 

[Tuesdak]

Unless you suck the system down and recharge it by weight you won't get a proper charge in the system period. I will stand corrected if you did just that. (And this can be undone with a good sized leak.) Gauges and pressures won't tell you the system charge - diagnose other issues, yes. If you are using recovery equipment, as required by law, it will tell you how much R134a comes out of your system and you will know for sure if it was low or not.

I can't stress enough these systems are charged by weight with a tolerance of 1/4 LB only because this is the capacity of the accumulator with a leakage reserve figured in. Running a system low leaves the oil in the evaporator and starves the compressor for oil. Some are more sensitive than others and we have a tougher compressor with a better oiling system than most.

Otherwise I suggest the system is low as this system is unique like this: the driver side is cold while the passenger side warms up indicating a low system charge. The driver's side gets air from the bottom of the evaporator. So when it gets low the top has no Freon to cool the air and the passenger side gets the hot air off the top of the evaporator. If you can't find the leak assume it's a slow leak on the evaporator that these trucks are known for and are very hard to get a Freon sniffer to hit on.

Freezing up - just look at the lines at the firewall for ice. Low charge or other issues can cause this. The 2003 has a memo to relocate the probe, but, this isn't an instant freeze up with instant loss of airflow. Thus you may have several problems at once.

The cans with the low side gauge are a quack cure wasting $50.00 of the pay a shop $100 labor to do it right.