No heat on 1994 C220.
A good friend of mine has a 1994 C220 and the heater does not seem to be working properly. It is quite cold here (-12C), and none of the climate control buttons do anything. Yesterday after he left it running for over an hour, he came out and the fan was running and it was tosty inside. The engine temperature seems to be reading fine on the gauge. Any ideas what might be the problem?