It has been two weeks since my blower fan stopped working correctly on the low speed options (1, 2 and 3 ). It only works on high speed (Option 4). At first, I thought that the problem was in the fan speed switch because Iʼve seen this problem before and when I told my electrician about it, he disassembled the switch and tried to clean it. Of course this solution didnʼt work. So, Iʼve decided to dig for the solution myself and I found that this is a
pretty common problem among E36 cars. The problem is that
speed 1, 2 and 3 are controlled by something called (Final Stage Unit on digital climate control units, Blower Resistor Pack on analog climate control units).
The 4th speed is actually uncontrolled, so, it simply bypasses the final stage or resistor pack units. That explains why the fan works on the 4th speed and not the other lower speed options. Anyway, I tried to find a DIY (Do It Yourself) procedure on how to fix this problem and I found one that was written by "Deem3" on bimmerforums (thank you Deem3 for the great write-up). Now take a look below. Itʼs a really simple procedure. I will be trying it this weekend to see how it goes. I will post more details about this job soon (hopefully)
.