My heat has stopped working just in time for the cold weather! The temperature control unit works fine except for the complete lack of heat (the buttons all seem to do what they're supposed to). The heat gauge on the dash shows that the engine is getting hot, but none of the temp. control settings (defrost, bi-level, etc.) make hot air blow. The air coming out of the system is the outside temp.-frigid! I recently rebuilt the vacuum pump after the diaphram tore and a little oil got in the lines. But this sounds like an electrical problem, no?
I recently got the Mercedes factory HVAC manual, but I don't know where to start with this problem. I have the vacuum and wiring diagrams and now have a rough idea of how the system works (it's complicated!).
Where should I start? What's the sensible order of things to check/test.
Thanks.