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BMW
328i
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Blower Final Stage Fan Resistor May Fail on BMW 328i

Problem Description and Possible Solution

The blower final stage fan resistor is known to fail. Symptoms are the heater fan speed varies regardless of the setting, the fan will not turn off when the car is switched off, or the fan will not switch on at all.

Problem Data
RepairPal Verified
Average mileage: 104,534 (900–219,726)
11 model years affected: 1997, 1998, 1999, 2000, more2007, 2008, 2009, 2010, 2011, 2013, 2015
64 people reported this problem
Comments
Viewing 1 - 20 of 23 comments
The air conditioner would work, and you could tell it was cold but the air would not blow out of the vents. Also this would happen off and on for about 6 months. The air conditioning would work and blow cold air, then it seemed like on the really HOT days it would not blow the cold air at all, so i had enough!!! Replaced the final stage transistor and Yeah that fixed the problem!!!!!!!!!!!
Air suddenly stopped coming out of vents one day. Sounds like it is trying to work but nothing comes out. My dad looked at the gauges inside to test them and as he put them back, ready to try something else, it suddenly started to work. By the next day, it wasn't working again.
Blower intermittently would shut off, and fan speed was sporadic. So I opened the FSU or (final - stage - resistor unit) to find that one of the prongs to the main power connector was shorting causing the prong to partially disconnect from the circuit board. Possibly moisture could have been the cause!
Air shuts off when after being driven for a couple of hours. Then will come back on after a while.
Air and heat blower is doing its own thing. It goes high to low constantly. The biggest problem is that it stays on after the car is shut off.
The AC fan blows at random speeds without being touched. The air coming out is cold, but set on maximum, it will blow hard and then soft then somewhere in the middle and fluctuate the entire time you are driving.
A/C starts and stops unpredictably as if a connection is loose.
Perhaps I will have to try replacing the final stage fan transistor whatever that is.
the a/c would turn on when it wanted,first i thought it was a loose connection point, wrong! I'm now going to replace the final stage resistor, pray to god. I live in Las Vegas, and it's HOT!!!!!
Fan in op despite any setting car turned on and off to verify settings otherwise car functions well without fan there for Nora air-conditioning or heat vehicle has automatic climate control with manual settings neither work
Neither the heater or A/C is blowing air. I live 150 miles from the dealership and what really irks me is that I only have 900 miles on the car!