SERIOUS ELECTRICAL PROBLEM!? HELP!?!

[chasers36]

HEY EVERYONE!

So, let me just preface by saying that this week has been EXTREMELY high energy and chaotic I think I might just need to go find a dark deep cave to go hide in for a bit lol. Cut my toe open in a NAPA Auto Parts store yesterday because their whole store was somehow unaware of a deadly 90 degree bent metal floor seam in one of their aisles, and my foot had to find it. OUCH. Taking that as a sign and NEVER buying from NAPA again. Might sue even ... ANYWAY lol down to my serious issue at hand with my 2001 BMW X5 E53 4.4i.

I think my baby was on the verge of bursting into flames today.

Today's temps were high, almost 100 degrees F. After an almost 2 hour journey returning home from my parents, I stopped at the gas station to fill up. After I left the gas station I didn't turn my AC on, because i'd been running it most of the trip back, without issue, and wanted to give it a break and feel the wind in my hair for the quick 10 minutes i had left to get home. Well, about halfway their I said screw it, i'm hot, so i click the AC button to turn it on, and all of a sudden I get a nasty white smoke plastic chemical burning smell coming from my vents. I immediately turn the AC off and turn the fan speed off until the climate control completely shuts down on the display, but the blower motor STILL WAS RUNNING! I frantically pull over immediately and shut the car off, but the BLOWER MOTOR STILL SOUNDS LIKE ITS ON, but the car is totally shutdown at this point. I rush her home in the next 3 minutes, and disconnect my battery. The fan has stopped. SO WHATS THE ISSH HERE GUYS. I'm pretty sure if I left the system on I would have had a fire. I'm extremely concerned, and need pointed in the right direction for finding the culprit. I've seen NUMEROUS stories of these things just bursting into flame due to random electrical issues. I'm tryin not to flip out as well because HOLY moly does that burning smell HORRIBLE.

I have checked all the usual places that I can check. Fuses in the glove box were good, no burnt fuses or melted wires. I have not done any aftermarket wiring besides my android headunit stereo. This definitely seems like a failed motor or melted wiring somewhere in the HVAC motor or the AC system. The smell is ACRID horrible chemical melted plastic smell.

[wpoll]

Have you checked the FSR? It is in the airflow for the vents... so if it smokes up, the smoke will go straight to the cabin....

And if it fuses itself, the fan motor won't stop.

https://youtu.be/7_D-Ki_Kk2k

[Overboost]

Sounds like the FSR for sure. Cheap fix, a lot of threads here on the procedure.

[upallnight]

You sure it's the fan for the HVAC and not the aux fan? Aux fan is known to cause the X to burst into flame. When you turn on the AC it also signal to turn on the aux fan. If you have bmw scanning software scan the X and see if you have a fan fault code in the DME.

Smell around the aux fan and see if you smell that acrid smell of burning wires.

[wpoll]

Originally Posted by upallnight

You sure it's the fan for the HVAC and not the aux fan? Aux fan is known to cause the X to burst into flame. When you turn on the AC it also signal to turn on the aux fan. If you have bmw scanning software scan the X and see if you have a fan fault code in the DME.

Smell around the aux fan and see if you smell that acrid smell of burning wires.

While I agree that the aux fan has to be another possiblity, the fact that the dash blower runs with the car turned off points to the FSR (initially anyway...).

[chasers36]

Originally Posted by Overboost

Sounds like the FSR for sure. Cheap fix, a lot of threads here on the procedure.

You guys are live savers! I had bought this part awhile back when i first purchased my x5 because i noticed the fan speed fluctuating randomly and just being inconsistent in general and i read up on it and it said it was that. but i never got around to replacing it because it started acting normal again so i thought nothing more of it, and didnt know of its potential to go up i smoke like that! that was over a year ago! it must have finally hit its frying point with the heat today, and i guess the universe was telling me to put the new one in already!

[Clavurion]

While renewing FSR clean the connector pins and use some contact paste on them. Poor contact on those round pins is not uncommon and can also cause serious heat load on the connector.

[upallnight]

Originally Posted by wpoll

While I agree that the aux fan has to be another possiblity, the fact that the dash blower runs with the car turned off points to the FSR (initially anyway...).

The hvac fan is tied in wit the ignition key and with the ignition off, the fan should stop, however, the aux fan is wired directly to a 50 amp fuse circuit so the power is LIVE all the time. Even with the key off the fan will still have power to it. The fan control circuit in the fan might have shorted that a pwm signal is no longer required to maintain the power to the fan. I posted first hand what happens when the fan control circuit short out.

[chasers36]

the remains...

[wpoll]

Smoking gun - literally!