Aux Fan Question
 

Can anybody tell me how to test Aux fan connector for power? About 2 weeks ago I rear ended somebody on the highway in my wifes 2005 X5 3.0 with 100k miles ( 5mph crash). The bumper clips near the fender broke, the mesh in the bumper, fog light covers shot out ,and bent my OEM bull bar a lil bit. I didn't think anything happened to the fan. Fast forward to this past Saturday. Wife left the truck running in the driveway with A/C on for 45 mins ( because she wanted to keep sons birthday cake cool :rolleyes:while everybody got ready for his party). Just as we were getting in the truck to leave, KABOOM, expansion tank exploded. We hurried toput everything in my BMW 3 series and went to the party.. I swapped out the tank and noticed the A/C doesn't blow cold when sitting at red light , or sitting in traffic. I rarely drive her truck so I don't know how long it has been like this. I tried testing lil plug with multimeter for 12v but came up with nothing) Is the lil plug that clips on top of shroud the power source ? Or is that a temp sensor? Is the Big plug below the lil one the power source? ( think wiring )I checked all of the fuses mentioned in other posts. Does anybody think the accident killed the fan? I just wanna be sure before I shell out $225 for a new fan. Thanks for the help .

P.s , I scanned the truck with GT1 and there were no errors related to HVAC or Aux fan,ect . I read somewhere that a problem with fan would show up on "BMW software" which is confusing me now .

It's the bigger plug that clips to the side of the fan shroud. The little plug should go to the f.auc sensor (senses air pollution and switches to recirculate).

12V on the big plug is neccesary but doesn't tell the whole story. The other wires are ground and a pulse-width modulated speed signal that the fans digital electronics decode. Not a "dumb" 0v = off, 12v = full on sort of thing.

If you have the software, you should be able to activate the fan manually and see if it runs.

When you used GT1 fan should have come on for a few seconds after test was started.
Fan won't come on if AC low/high pressures are not within a certain range.
Also when you first start engine fan should turn over a few times and stop until it sees correct high/low pressures.
You might be low on Freon.

Thanks for the replies . I will test for 12v this morning then check freon level

Fan fault will be found in the DME module, not the HVAC module.

The only code on DME that was remotely related to A/C aux fan was a code for the recirculator button . . I didnt think much of it because it seemed to be working properly . Im gonna scan truck again when i get home today .

Well, after searching around the internet a while , I decided to do an electric fan swap. I read a few threads from E46 Fanatics and bimmerforums . Being that I have to remove the bumper to replace the fan anyway, im gonna remove the Aux fan, remove the mechanical fam and install this in its place . It is totally plug and play unit . This rules out any chanve of the fan exploding (famous waterpump bearing failure) and taking out other parts. Pelican Parts - Product Information: 17-11-7-561-757-M202

I plan on doin a DIY write up for those who are interested

You must have wonder onto this forum by mistake. If it is plug and play you must have an E46 and not an E53.