Hello All,


I have just purchased my first Merc. '01 grand marq LS


I have a weird high pitched whine that occurs when I turn the auto climate control on. If I turn it off - whine stops. Then it will re-occur while a/c is off and then if I hit the on switch it will stop. It seems that if I put a load on the control circuit by changing the fan speed or turning it on or off, it will stop the whine.


The whine is very high pitched and I originally thought it was in the radio. This whine happens when the radio is on or off. So I think it is located in the a/c controls.


Any thoughts????





Thanks,

is the whine inside or outside of the cockpit?

Its inside the cab. Its sounds electrical. I'm pretty sure its coming from the a/c and not the speakers. And it is definitely occuring when I start the max, norm, or auto a/c cycles.


If I set it to flr/def it seems to never occur.


Thanks,





Phoenix