Here's what a bad Aux fan looks like

[TiAgX5]

The best way to avoid electrical component failure?

Three simple steps.....

1) NEVER operate a vehicle with a failing alternator, output below 13.3 V.

2) NEVER continue to start/drive a vehicle when battery resting voltage is below 12.2 V.

3) NEVER jump a car and drive off, just hoping the alternator/battery are fine and/or the drive will fix any issues.

Electrical 101, voltage drops, amperage draw increases. more amperage draw=more heat!

Over 14yrs and 200k miles here, OE aux fan & alternator, 1 Genuine BMW FSR.

[oldskewel]

Originally Posted by J.Belknap

...
When the aux fan fails AC refrigerant temp goes up, pressure goes up, the compressor will purge excess high-side pressure, after a cooldown there wont be enough refrigerant volume in the system to allow the compressor to activate again.

First off - you answered the exact question I was thinking before I read this - why do that other AC work just because the fan failed? Thanks, and also thanks for the cool pics - always good to see documented failures.

But I've never heard of anything like this - a designed venting of refrigerant. It seems to go against the (perhaps overly) stringent regulations on CFCs and HFCs. How???

[upallnight]

Originally Posted by oldskewel

First off - you answered the exact question I was thinking before I read this - why do that other AC work just because the fan failed? Thanks, and also thanks for the cool pics - always good to see documented failures.

But I've never heard of anything like this - a designed venting of refrigerant. It seems to go against the (perhaps overly) stringent regulations on CFCs and HFCs. How???

Better to have a little refrigerant vented then to have the system explode and release the entire system of refrigerant because of the high pressure.

[semcoinc]

Originally Posted by bcredliner

I don't recall anyone mentioning they have done PM on Aux fan though I don't look at all threads. To me it is one of those parts like a water pump. Sooner or later it will wear out, just hope it is a long time.

I seldom lubricate electrical parts because of the risk to get the lub somewhere that will destroy the part.

Some replace the mechanical fan before there is a problem as there have been fans that have thrown blades and caused other damage and the performance of the mechanical fan can decline but go unnoticed. As you can see by this thread I don't think much of mechanical fans.

I am still running the original aux. fan. When it dies it dies. Not feeding it any vitamins.

I use an aviation product called CorrosionX which loves electrical connections



and provides lubrication as well. It is also a great (but expensive) rusted fastener release. IMHO, better than PB blaster but like I said, more expensive.

Corrosion X - from Sporty's Pilot Shop



Mike

[mgbmwx5]

Originally Posted by semcoinc

I use an aviation product called CorrosionX which loves electrical connections



and provides lubrication as well. It is also a great (but expensive) rusted fastener release. IMHO, better than PB blaster but like I said, more expensive.

Corrosion X - from Sporty's Pilot Shop



Mike

This product can also be purchased on ebay without the $45 shipping hit that the pilot shop charges. Here are couple of links:

Corrosionx Corrosion Inhibitor 90104

CORROSIONX 90104 Corrosion Inhibitor Penetrant Lubricant | eBay

corrosion x | eBay

[TiAgX5]

I use CRC 6-66 marine, can be purchased from any Fastenal location. No shipping.