If it cools o/k while driving I would start by looking at the cooling fans. Sounds like they are not pulling the heat away from the condenser. If the vehicle has a clutch fan instead of electric fans it may very well need replacing
it makes a tornado
it makes a tornado
Needs a recharge
Most likely cause is an inoperative condensor fan.
We perceive an object as hot or cold according to how fast its particles are moving. The faster they move, the hotter the object.
the humming sound is causing the heat? Your fan clutch has failed, or the radiator/condensor have dirt blocking airflow.
Heat is defined by how fast molecules are moving. Fast moving molecules will have a higher temperature than slow moving molecules. The kinetic energy of the hot air is transferred to the cold air, which means the cold air becomes a little warmer, and the hot air becomes cooler.
Simple, you ac does not blow cold air even though you have it turned on and the temperature set to cold.
the AC is run by a belt that is connected to the engine. if you turn the engine off, the belt stops moving. No belt movement means no power for the AC. the fan will only blow air, not cold air.
If 1993 suburban rear ac not cold how can check the expansion valve?
recharge ac
mic or moving iron coil is instrument type works on ac and dc