Today’s Symptoms:

I thought this vehicle was fixed but this 2001 BMW Blower is reported acting up again. As per my customer, when he was driving and the AC was on, all of a sudden… the blower motor would quit. If he waited a few minutes, the blower motor would come on again. This took about a few minutes and quit again. This just kept cycling on and off.

Diagnostics for 2001 BMW Blower problem:

Using the wiring diagram for 2001 BMW Blower, take a close look at your blower resistors. Just came across a fix which says, the resistor on this vehicle does not go often unless it runs ONLY on high speed. BMW mechanics are saying that the most common culprit is the FINAL STAGE UNIT. This is like a module or computer or transistors that activate the blower motor. To test, tap it with AC turned on. Then if you hear the blower suddenly runs, then that module is the culprit! You can also try wiggling the wires and do the same results in case you have a blower loose connection.

Another test for 2001 BMW Blower Final Stage Unit:

Looking again at the blower wiring diagram, check for power at pin # 2 or red blue wire. You should get 12v there. Then look at your top pin # 1 or black green wire. That should be your 12v power going to the blower motor. Then looking down on pin # 5 or red green wire, you should get the ground voltage reading. Any ground wire means a max of 0.250 v or higher should show you that ground wire is a shorted. I might be mistaken with the 12 v on pin # 1 but you can reverse it with pin # 5 if I am wrong. The thing is, one of them is either power or ground. You can’t have both. If both are 12v or 0 voltage, unplug the 2 blower wires and test again. If the reading is both 0 or 12 volts on the blower terminal wires, then the module is no good.

Quick test for 2001 BMW Blower:

If you can access the blower motor, unplug both 2 wires going to it. Then supply your own battery voltage and ground to it using 2 jumper wires. If the blower runs, then the final stage unit is really defective. Just make sure you check the continuity of the wires between the blower and final stage unit.

Final fix for this 2001 BMW Blower:

I am still waiting for the ATS member to give me an update as to the final fix. I will give you guys an update as soon as he gives it to me.

Please don’t attempt to this yourself without guidance from a licensed mechanic to prevent damage to your AC components.

Thanks,

Richard