Hello, I have a 1996 328is. I have recently run into some issues with the a/c and heater system. The control unit was replaced last year, but that seems to be ok. The issue that the air randomly shuts off, and even though i can feel a tiny bit of air coming out of the vents, i cant adjust it to blow harder. I need this issue fixed soon as soon it willl get colder, and i won't be able to de-fog or de-frost my windshield. Thank you.
An electrical problem may have occurred if there is a leak. The system has three major components and a few smaller ones. Most of the time, your problem lies in at least one of the three big ones: compressor, evaporator, and condenser. It also has a small metal can, containing desiccant, which should be changed whenever the system is opened. The components are in different locations in the car, so there really is no such thing as replacing the whole air conditioner as many people think they have after a major repair.
I had this problem last year, basically couldn't control the blowers at all and they did whatever they wanted. I went onto e bay originally resided to having to buy a new temp control panel (around about £200), however I typed in 'e36 uncontrollable fan' and got a result from some guy who was selling the fix for under a tenner. I took a punt and was pleasantly surprised.
I got a replacement resistor and an idiot guide on installation. Took less than an hour to do and all that was needed was a screwdriver and solder iron. Plugged the control panel back in and worked like new.