Sitting in the car the other night, with the engine off. Was getting pretty cold, so I decided to turn the heating on (ignition was off, when I discovered that the climate system would not work. If I understand it correctly the system should work until the stored heat runs out or the battery drops below a certain voltage. Well I had just driven for 8 hours, so I assume that everything was OK. It has worked fine in the past when I have left the car to go shopping. Anyone have any ideas??? or is it another trip back to the dealer.....

 

Are you talking about the rest switch??

 

Rest switch? Not sure what you mean. In the past when I have left the car and turned off the ignition, I press the "Auto" and the heating will maintain the temperature I set until it switches off due to voltage drop or heat loss. Does that help?

 

You said it yourself, if the voltage drop rest switch feature will not work. A possibility that the battery is going?

 

Sosh, just checked, yes the "rest switch".

Emro, thanks for the idea, I had thought the same about the battery being the problem. However I had just driven for 8 hours non-stop. When I decided to put the heating on the engine had only be off for about 5 minutes. However I will have the battery tested.

 

Tried my 02 ML500. Works with the Rest switch but if I just push auto with the ignition off does nothing.

 

Sosh, just tried it again, all dead. Will take it to the MB dealer!! Best make use of the warranty!!!