MVoorhees

2011 A8L 4.2L 95K miles
Hi All,
Recently, My car has been producing a horrible electrical/burning/melting smell when the fan is on. Doesn't matter if it is hot air or cold air or what the fan speed is. The smell is not continual, but rather come in "waves". I have been working with a very reputable independent shop who suggested and believed it was the front blower. They replaced the blower and resistor about a week ago and mentioned that they found some burnt debris is the blower housing so they believed that was the issue. A week later, today was unbearable. So either the new blower and resister have failed (certainly possible I suppose) or something is CAUSING them to fail, OR the root cause is something unrelated. I figured I would turn to the wisdom of the crowd here!

Thanks in advance!

Marc

ppinto1

I had something similar. Ended up being an auxiliary coolant pump in the cowl. When this happened, smoke blew into the car through the vents.

MVoorhees

Was your smoke sweet? Or acrid? The shop said they would check that but would expect it to have a sweet smell if that was the issue . Thanks for the tip!

ppinto1

It was acrid. The pump didn't fail in a way that allowed coolant to escape - so no sweet smell. It was the smell of burning electrical insulation. This was accompanied by a code. Let me see if I can find my old post about it and get back with the code.

ppinto1

Address 08: Auto HVAC Labels: 4H0-820-043.clb
Control Module Part Number: 4H0 820 043 H HW: 4H0 820 043 H
Component and/or Version: Klima 4 Zonen H20 0110
Software Coding: 488120BEC8
Work Shop Code: WSC 02313 785 00200
ASAM Dataset: EV_AirCondiFront 001050 (AU64)
ROD: EV_AirCondiFront_001_AU64.rod
VCID: 2541810F24A8F06EC2-8070
2 Faults Found:

0378 - Coolant Circulation Pump
B10D0 04 [009] - Internal System Fault
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 3
Fault Frequency: 17
Reset counter: 223
Mileage: 108646 km
Date: 2017.01.21
Time: 18:03:06

Voltage terminal 30-Data: 14.2 V
Outside air temperature-Data: 12.50 °C
Interior temperature-Data: 25.00 °C

0379 - Supply Voltage Terminal 30 for Coolant Pump
B11D5 01 [008] - Electrical Failure
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 3
Fault Frequency: 1
Reset counter: 8
Mileage: 136245 km
Date: 2018.06.19
Time: 19:36:51

Voltage terminal 30-Data: 14.0 V
Outside air temperature-Data: 28.50 °C
Interior temperature-Data: 26.30 °C

ppinto1

Please note, the above codes did not cause a malfunction indicator. They had to be found by scanning the controller for (I think) HVAC.

MVoorhees

Thank you thank you!! I have passed this on, we will see!!

spow

I had the same or similar issue just a few weeks ago. It was the auxiliary coolant pump located just next to the fresh air intake. It was leaking drops of coolant onto the electrical connector, which produced periodic puffs of terrible smelling smoke. I thought the smell was electrical at first as well. It was not the typical coolant smell since it was being completely burned. I was also seeing a very slow loss of coolant. I ordered the part on Amazon and easily replaced the pump.

MVoorhees

Goddamn you guys are fantastic. Nailed it in 1! The shop (and my wallet) appreciate you guys preventing then from wasting their time hunting around for Gremlins

ppinto1

Great news!