Could this be why I'm experiencing A/C difficulties with my 2000 TT? If I'm sitting in traffic idling, the A/C stops blowing cold air. It just blows hot air. But when I get moving again, over 20mph, it starts blowing cold again. Seems like the A/C kicks itself off when I'm idling or going slow but kicks back on when I'm moving faster than 20mph. What does this sound like to you?

Also, when I take extended trips, say 3 hours or more of continuous driving, the fan doesn't blow as hard as it does when I first take off. What I mean is that after 3 or more hours of continual driving, the fan speed isn't the same as when I first started. Even on full blast, the fan speed is significantly slower than what it is when I first start driving.

 

your refrigerant may be low. that will cause the evaporator to freeze (ice) and restrict air flow. you may also want to check and make sure your a/c condenser fan is working (passenger side radiator fan).