Auto AC – understand the basics. Most issues will be low on freon but check a few things first. This basic troubleshooting will help diagnose the issue.

Image result for auto ac diagram

A/C has built-in sensors – hi-pressure, lo pressure designed to protect the compressor. Temp and Fan motor controls.

  • 1- IS air blowing from vents? – check the blower fan
  • 2-Is air coming from the vent cold- NO could be relay, fuse, Rad fan, or too little of too much freon.
  • 3-Check the 40 amp fuse for the cooling fan. If fuse blows could be fan issue or short.
  • 4-Check the Relay
  • 5-Add gauge to check freon pressure.
  • 6-Add freon if needed.

One case I was working on was the car had been hit front side and repaired. The 40 amp fuse was blown for the cooling fan, replaced fuse AC started working but then the fan smoked and blew fuse. Will replace fan assemble and resistor at 120$ for the part.

Fan assembly

Fuse JCase 32V 40A 1-piece Card
40 Amp fuse 5$