GM-GMC: air conditioning trouble gmc jimmy, gmc jimmy, air cond

Question
GMC Jimmy, the air cond is ice cold when driving, but when idling it becomes significally less cool and does not cool off the vehicle. Is there a problem that needs attention, an adustment that can be done to fix this or is this a normal must live with condition. thank you

Answer
A/C systems are less effective at slow engine and vehicle speeds.  So, on a hot, humid day, an owner should expect less cooling at slow speeds.

If you want to be sure, take the vehicle to a shop and have the A/C system checked for the correct amount of refrigerant.

Your description would tend to make me believe that your A/C system is working correctly and, is perhaps just a little low on refrigerant.