Heater works... then doesn't. Makes clicking noise? Help pls

[sammywilko]

Hi

I'm not the best when it comes to cars but god loves a tryer so i'm willing to give it a go... I managed to "fix" what i thought was the problem last year when i cleared out the microfilter and the heater began to work. It worked all last winter and then all summer. It has just started going wrong again though. I tried clearing out the microfilter again but this time it was clear so now i'm stumped. It sounds like the motor (if there is one) is trying to make the fans work (if that's how the heating system works). It just clicks or at least that's what is sounds like. There is air going to back windscreen heater but nothing anywhere else. The other thing that confuses me is that occassionally it works fine completely, like today when i started it and all the heaters worked fine. Then an hour later nothing.

Yours baffled.

[sammywilko]

Ooh, one other thing. It's a BMW M3, E36. '94.

Thanks in advance

[MitchT]

Sounds like the final stage resistor (fan motor regulator) is on its way out. Mine did this. Firstly working intermittently and then not working at all. The reason your rear window still clears is because it uses electrical elements on the glass, not air, so is not affected by the fan malfunction.