I should clarify my earlier message. The Climate Control power shuts off entirely. It will work with ignition on for a period of time which varies, but not in engine running mode. The fan shuts off and the air flow defauls to defrost. This varies according to the position of the dial as well. It works with less frequency as the dial is turned to a higher heat setting. This may all be related to your earlier reply, but I would like to be sure before I take it to a MB garage as it is 2.5 hours away. Thank you.
Kevin E. Ryan