AUX fan and A/C stopped working.

[Wishno87]

Is there anything that could kill both of them at once? I did replace the aux fan fuse but that didn't do anything. This is a 95 525i wagon. Thanks guys!

[shogun]

There are 2 relays and 3 fuses for the aux fan. Check them http://shark.armchair.mb.ca/~dave/BMW/e34/e34_95.pdf
accdg to the ETM there are 3 fuses for the aux fan, 9, 25,29

turn the aux fan by hand, does it turn easy or blocked? If blocked, the magnets in the aux fan motor got lose and block the motor.
the test like this http://www.nmia.com/~dgnrg/page_20.htm

[Wishno87]

Awesome thanks I will look into that. Will a non-op aux fan prevent the compressor from engaging?

[shogun]

when the compressor /AC is on, the aux fan runs automatically on low speed. when you push the A/C button, it provides power to the low speed Aux Fan relay, explained here on the E24 forum, same system
https://www.bimmerforums.com/forum/s...ut-not-with-AC

The AC needs the aux fan, if aux fan not working, AC will probably not start

[demetk]

The pressure switch will open below 1.5 bar if there is a low refrigerant charge. If this happens, the IHKR will not allow the aux fan and the compressor to run.

[fo3]

The pressure switch will open below 1.5 bar if there is a low refrigerant charge. If this happens, the IHKR will not allow the aux fan and the compressor to run.

That seems more likely.
If the aux fan wasn't running for it's own reason (fuse or motor), then a/c would work briefly until it cuts out because no cooling (due to aux fan fault)

But like demetk said, more likely compressor isn't turning on due to low pressure fault, or compressor, or compressor clutch fault, so aux fan doesn't have a need to run anyway.

[CarterH]

So not that I want to take over this thread, but my aux fan hasn't moved in two years and my AC runs just fine. Is this bad? The AC runs perfectly and is very cold. The fuses for the aux fan look fine and since everything else works fine, I've never bothered to get it fixed.

[demetk]

So not that I want to take over this thread, but my aux fan hasn't moved in two years and my AC runs just fine. Is this bad? The AC runs perfectly and is very cold. The fuses for the aux fan look fine and since everything else works fine, I've never bothered to get it fixed.

The 89 has a simpler system. You can check aux fan function by jumping the rad temp switch, pins 1 & 3 for high speed and 1 & 2 for low speed. If the low speed doesn't work the aux fan resistor is blown. The a/c system uses the low speed mode.

[fo3]

So not that I want to take over this thread, but my aux fan hasn't moved in two years and my AC runs just fine. Is this bad? The AC runs perfectly and is very cold. The fuses for the aux fan look fine and since everything else works fine, I've never bothered to get it fixed.

It can work like that, that's why agreed before saying the OP's fault was more like a compressor not running. I'm surprised your's is running cold. I once owned a ford courier/ranger truck and it didn't even have a aux/electric fan at all, just a clutch fan like bmws have and when the weather was real hot or I was stuck in traffic the a/c didn't work very well at all. But 80% of the time it worked OK despite having no running elec fan in front.

It would make the discharge pressure higher though, increasing chances of leaks so I'd fix yours if you could. Start by checking the relays I guess. A simple job would be swapping the two of them as the high speed has probably never run/been used. (they're in a small box just in front of the shock tower - where m50s have the air box, AMF, intake boot etc). E: looks the same for you, small box near the power steering reservoir in front of the shock tower)

[CarterH]

It can work like that, that's why agreed before saying the OP's fault was more like a compressor not running. I'm surprised your's is running cold. I once owned a ford courier/ranger truck and it didn't even have a aux/electric fan at all, just a clutch fan like bmws have and when the weather was real hot or I was stuck in traffic the a/c didn't work very well at all. But 80% of the time it worked OK despite having no running elec fan in front.

It would make the discharge pressure higher though, increasing chances of leaks so I'd fix yours if you could. Start by checking the relays I guess. A simple job would be swapping the two of them as the high speed has probably never run/been used. (they're in a small box just in front of the shock tower - where m50s have the air box, AMF, intake boot etc). E: looks the same for you, small box near the power steering reservoir in front of the shock tower)

Alright, I'll take a look at the relays. Will there be any obvious signs that they've failed? I know that if the relays are fine then it's probably the resistor but I recall that you have to take off most of the front of the car to get to it.

I did have the compressor replaced last year too since my previous one broke. The AC guy I went to said that it was stuck on and pretty much destroyed itself. This one though has been regularly checked and appears to be fine and the shop didn't seem concerned about the aux fan.