Q: AC stops working when idling

It is possible that your compressor clutch is producing more drag than usual, causing the near stall at idle. When the engine RPM is raised, the belt rotates faster, forcing the compressor to spin.

It is also possible that you are not getting enough air flow through your condenser on the front of your vehicle. When driving at higher speeds the air is forced through the condenser naturally. At idle, there is far less air going through the condenser and if it is clogged, the air the cooling fan produces may not be enough to cool down the refrigerant, although this would not explain the near stall.

A final possible cause of this issue would be that your cooling fan or A/C fan is not working. This would cause the engine to possibly stall if overheated and would certanly cause a lack of air conditioning at idle.

I would suggest having your air conditioning system inspected by a professional mobile mechanic to diagnose the issue, and recommend the best solution.