Aux fan :(

[ants_oz]

Another sufferer of the famous aux fan failure I ordered a replacement off eBay this afternoon, so should be here next week sometime. I guess it'll be off with the bumper.

I only ordered one of the cheaper fans, as I figure at the price difference, it was well worth a shot. Will see how that goes.

[Joshdub]

I just did mine last week. I was able to pick up a new Behr unit for 300 shipped. It is a really easy job. Good luck.

[SMOKEY53]

Unlucky but better now than on a 40deg day in summer. I have used an aftermarket one on my e39 before, it did not end well. Kept flexing and rubbing against the shroud. Would deform in heat and make a racket until i pressed it back in..... I may have been unlucky but think I'll stick with genuine next time.

[ants_oz]

Yeah, I'm hoping the quality will be tolerable. My plan at this stage is to remove the existing fan and see how many of the old parts I can retrofit onto the new motor. With luck, the only new parts I will need to use is the motor and electric supply cable. Fingers crossed...

[Riba]

Originally Posted by ants_oz

Yeah, I'm hoping the quality will be tolerable. My plan at this stage is to remove the existing fan and see how many of the old parts I can retrofit onto the new motor. With luck, the only new parts I will need to use is the motor and electric supply cable. Fingers crossed...

It is not that simple unfortunately. There is more electronic witchery on that fan assembly than just the motor and the cabling. Actually I suspect it is fan regulator that fails most of the time and not the motor itself.

[upallnight]

If the 50 amps fuse is blown, yep the fan has failed. But if the 50 amp fuse has not failed and your ac is not blowing cold, I would check out other possibilities before replacing the fan. Not saying that it isn't the fan, but there are other reasons why an ac system is not blowing cold.

[Riba]

Originally Posted by upallnight

If the 50 amps fuse is blown, yep the fan has failed. But if the 50 amp fuse has not failed and your ac is not blowing cold, I would check out other possibilities before replacing the fan. Not saying that it isn't the fan, but there are other reasons why an ac system is not blowing cold.

I had AC give up on me two months ago (In Kuwait, mind you). The AUX fan was not turning on, or was running erratically. I was almost sure it would be the fan, but I took the car to a local AC specialist, he found a leak in AC line. Local dealer did not have it in stock so he repaired it, replaced the O rings at the firewall and AC has been running strong ever since.

[ants_oz]

AC works perfectly even when the vehicle is travelling slowly. It does not, however, work very well at all when the vehicle is stationary. That is why I suspect the fan. That and the fact it pulses when the vehicle is turned on, then does nothing afterwards.

[upallnight]

The pulse is normal. It's a test to determine if the fan is good. When the fan spins, it send a dc volt back to the dme to let it know that it has spun when the DME commanded it to turn on. You can get the X scan with BMW software and it will tell you if the fan is faulty.

Since the ac doesn't work when it is stationary, could be you are low on refrigerant. When you are moving the engine is spinning faster and thus, the compressor is also spinning fast. At idle the engine is only spinning at 700rpm.

You will need to get the low side and high side pressure readings and the ambient temp to determine what is the problem.

[nice1guv]

Originally Posted by upallnight

You will need to get the low side and high side pressure readings and the ambient temp to determine what is the problem.

Do you know what the low and high side pressures should be reading?
I assume these can be read with DIS?