2009 Mercedes ML550 ac runs hot drivers side cold passenger side
Hello all, New member here and my question regards my ac which can suddenly switch to front defrost and then run hot, very hot, on front defrost and drivers side vent and at same time blow cold air out passenger center and side. Freon level is good. Compressor engages when turning on ac. Any ideas or experiences would be gratefully appreciated.
Thanks,
Jim E.
Your issue seems to revolve around a mix of HVAC (Heating, Ventilation, and Air Conditioning) concerns, both with the mode door actuators and temperature blend door actuators. Here are a few things you might consider:
Mode Door Actuator: This is responsible for changing the airflow direction (e.g., from dash vents to defrost). A faulty actuator can cause the air to blow out of the wrong vents. The sudden switch from AC to front defrost suggests there may be an issue with this actuator.
Temperature Blend Door Actuator: This controls the temperature mix. If it's malfunctioning, it can cause inconsistent temperatures from different vents. Your experience of having hot air on the driver's side and cold air on the passenger side could be indicative of a problem with this actuator.
HVAC Control Module: Sometimes, the issue might be with the control module, which is essentially the brain of the HVAC system. If it malfunctions, it can send wrong signals causing erratic behavior.
Diagnostics: A proper diagnostic scan can sometimes pull HVAC-related error codes, which might help pinpoint the exact issue.
Physical Blockages: While less likely, check for any blockages in the ductwork or issues with the flaps that direct airflow.
I hope this provides some direction, and I'm confident that other members might chime in with their experiences and suggestions. Good luck!
Yes, it does help. Thank you very much for the info. I ran a scan using Youcanic that showed faults regarding said flaps. Quite a few flaps, I might add. I'm looking into those at present.
Again, thank you for the reply.
Jim E.