A/C has a mind of its own

[F1FL]

Hi all,

Having an issue with my A/C in my 2011 M3. The A/C does not operate at full power unless the engine is completely warmed up. It blows very dully and then all of the sudden it will blow at full power.

I've also noticed at times the A/C will completely stop or go down to the lowest speed when I come to a stop while driving. It then will come right back on seconds later.

Any suggestions would be greatly appreciated.

[Pig Farmer]

Your issue is almost certainly the blower motor wire harness, for which there is a recall. I’ve read that corrosion on the wires impacts the wires’ impedance which in turn screws with the blower motor regulator. I had the same symptoms and ended up fixing the wire harness myself. I basically unplugged the harness from the blower motor regulator, stripped the disintegrated insulatiom off the wires near the plug (without cutting the copper wire inside the insulator), soaked the plug and bare wires in vinegar for 30 minutes followed by a 5 minute soak in water and baking soda, rinsed with clean water and let it dry. Once completely dry, I coated the bare copper wire with several layers of liquid electrical tape, letting each coat dry before adding another coat. I even sealed the back of the plug where the wire enter the plug. This fixed the problem and I have had zero issues with the blower ever since.

[Shredicus]

Alternatively its probably covered under recall

https://bmw.oemdtc.com/163/safety-re...1-bmw-3-series

[bmwlover0725]

What everyone else is saying^^

Take it to the dealer. I just had this recall done myself.

[mapster37]

if your recall hasnt been performed yet, get it done. if its already been addressed replace the blower resistor

[F1FL]

Was the blower motor recall - fixed. Thanks all