e430 heater
 

still looking for help w 99 e430 heater trouble. heats only on one side. sometimes driver side, more often passenger side. when i unplug elelectrical connecter from monovalve i get heat from both sides. please help me trouble shoot this problem. thanks:book:

Sounds like you already have...heater valve is the most likely problem.

monovalve
 

Thanks for responding. I thought it was the valve but didnt want to waste $165 if I was missing something. Thought maybe it could be something in the control.Thanks again!