(1999 E36 touring, 328I/A, NZ New)
I'll say it from the outset, this is not the fan or fan speed regulator. The blower fan is 100% perfect.
My issue is heat. It will not regulate heat.
-32*c blows HOT air.
-31.5*c blows cool non heated air
-Temperature slider thingi: makes no difference if on max or mid.
I took out the pollen filter and breathed in enough soot to probably get cancer from it. Blew out the filter and put it back in which gave me much better flow.
I am not too sure what to check, I suspect it is electrical and a sensor in the HVAC box. The solenoid clearly works as I still get heat and good heat when on max, the system just seems to not know how to control the water flow to regulate heat and seems the solenoid is either open or closed. This is apparent for both climate zones.
Now for the curve ball, It seems to do this only in the morning and on the way home from work seems to regulate temperature OK. Maybe this is because the ambient temp outside is warmer and I am not able to identify the variance as well.
Any help is appreciated. If someone knows how to fix it I'll buy a box of their poison for the help. I am in Auckland North shore.
Side note: I have done 52,000KM in this car in 2 years, Never had a single failure or been left on the side of the road. This is the first thing wrong.