A/C

2002 MERCEDES BENZ ML500
140,000 MILES • 5.0L • V8 • AWD • AUTOMATIC
Avatar
ML500
  • MEMBER
  • 1 POST
A/C was not blowing cold. Put in two cans of 134. Now it will not cool at all and the compressor and auxiliary fan runs all the time whether the system is turned on or off.
I expected to see the compressor not turning with the system turned on, but it starts turning the moment the engine is started from cold startup. The auxiliary cooling fan normally only ran when the engine temperature was above 100c, but now it also runs constantly.
Aug 23, 2017 at 3:29 AM
Advertisement
Avatar
STEVE W.
  • ✓ASE Certified Mechanic
  • 15,200 POSTS
  • ASE Certified Mechanic
Put a set of actual gauges on it and check your system pressures. If it was empty it is probably still low. Mercedes Benz AC systems can be a real pain to work on because of all the extra sensors and controls. The pressures need to be correct or the system will act real strange.
Aug 23, 2017 at 11:52 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.