Electronic Heater Control Unit problems?

Just bought a 92 BMW E36 318is. I like the look of the car but FU*K it is a headache to own. Electronic everything and sensors everywhere. I have a dual zone analogue unit. The a/c doesnt work probably just needs a re-gas but im here because i cant figure out why i cant get heat from my vents. When i turn my car off i get a very strange sound from behind the dash near where the 'flap box' would be, but only sometimes. The directions all work the fan speed works but sometimes turns itself off and on. All the fuses are good the coolant has been flushed and bled. Been looking for hours and cant get a decent answer, but have come to the conclusion that this is just the way it is with electronic controlled everything type cars, and need to pay big $$ to get anything fixed... Please i like my car and would rather fix it than go back to my old school runners, so any advice will be appreciated

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: BMW Heater Valve Cleaning/Flushing

[Wayne 962]

The late-style electronic heater control units have a problem with a capacitor that goes bad on them. I don't have an article on that, on this site, but if you Google it, you will probably find it. It might be that issue, although I don't think they used that particular electronic control unit in 1992?

- Wayne

[Chattow]

Call me stupid if you wish but I had the same thing on my E36 92 model 325i

Then I found the Cold / Hot dial on the dash above the Air controls turn it towards the right for hot and left for cold

Just thought it might help using the K.I.S.S principle

[Manolito]

Chattow, if it makes you feel better, I drove my daughter's e36 the other day (used to be mine) and I did the same thing. I commented that I could not get hot air and she reached up and turned the control on the vent. She already knew that I am a dummy so no surprise.

[Chattow]

It Makes me feel better knowing tha I'm not the only one