e34 540i aircon and/or fan not working correctly :(

[danj 0]

Hello knowledgeable folk,

Just in the last 2 or 3 days I noticed the car wasn't keeping me cool like it normally does...

Initially I thought it was the air conditioning system (would make sense), except I've noticed now that even when I put the fans on full, there still does not seem to be a large volume of air coming out. There is a lot of fan noise, but not a lot of air, this is the same case whether I set the temperature to hot, cold, and have the aircon on or off.

To be honest I can't remember what the fans usually felt like on full power, but it really feels like there is not enough air coming out to cool or heat the car effectively, regardless of whether the aircon was cooling the air or not.

Any ideas? or should I just take it in to get checked by chch bmw

[BM WORLD 1283]

the resistor sword packs up and will work only on full speed.

also the pollen filters get blocked .

the heater taps fail and leak hot air in when its turned to cold etc ..

[danj 0]

Thanks, fan speed control is working fine, temperature control seems to work fine, even the front windscreen demister works!

There just seems to be a lack of airflow coming through the air vents!

[BM WORLD 1283]

Thanks, fan speed control is working fine, temperature control seems to work fine, even the front windscreen demister works!

There just seems to be a lack of airflow coming through the air vents!

change the pollen filter then . probably original one all stuffed up with leaves , dust etc.

burried right up above the divers feet on the side of the heater box .

try this link , just remember the pics are form lhd cars .

about photo 5 onwards applys.

http://www.nmia.com/~dgnrg/page_4.htm

[mtk540 3]

I recently had something similar in my E39. The heater fan seemed to have a mind of its own. Stops, starts, slow, full on. There was no control of the airflow whatsoever.

Then I saw an article in the June 09 issue of Total BMW that pinpointed it straight away as a faulty final stage resistor or "hedgehog" due to its shape. It regulates the speed of the blower fan. I had it replaced and the aircon goes fine now. Apparently a well known problem.

It can be a DIY but requires getting in under the steering column and taking bits out.

[danj 0]

Thanks brent, microfilter was blocked... that fixed my airflow problem.

But the aircon still isn't working Can you get the old systems regassed? It's probably low...

[*Glenn* 854]

Thanks brent, microfilter was blocked... that fixed my airflow problem.

But the aircon still isn't working Can you get the old systems regassed? It's probably low...

It may not need a retro fit. Check with an aircon repairer in CHCH...it may have a leak though

[danj 0]

thanks glenn, got it regassed, doesnt appear to be a leak, still not working, so it's in getting serviced... this could be expensive

edit: all fixed, there was an intermittent power supply problem to the compressor (as well as being low on gas), so it's all going again now. Thanks guys (even though I didn't fix it myself it's nice to be able to be somewhat informed when talking to the service staff, so your guys help was appreciated).

Brent are you the one on trademe selling those BBS wheels?

Edited October 14, 2009 by danj

[danj 0]

Problem not fixed, compressor appears to be blowing fuses This seems to happen randomly after a couple of days use, has happened twice now and can find no connection with any particular action that appears to be causing the fuse to blow.

Suggestions... time for a new compressor?

[BM WORLD 1283]

just swap the ac pump over for another . the clutch packs on them pack up short out etc .

easy job to swap over then regas.

also check if the front aux fan is running when the ac is turned on ,

common fail is the fan resistor mounted in front of the fan.

[danj 0]

just swap the ac pump over for another . the clutch packs on them pack up short out etc .

easy job to swap over then regas.

also check if the front aux fan is running when the ac is turned on ,

common fail is the fan resistor mounted in front of the fan.

Cheers, will check it out. When you say swap the ac pump for another, are you referring to the compressor... or something different? cheers.

[BM WORLD 1283]

Cheers, will check it out. When you say swap the ac pump for another, are you referring to the compressor... or something different? cheers.

yes thats right a/c compressor

[*Glenn* 854]

If the system is charged. It is against the law to release the gas.. $10,000 max fine if you get caught. You must get it degased by a licenced repairer. Just get them to recheck it for you and give you a price on fixing it. If they said it was fixed properly before.. tell them its not... and get them to sort it

[danj 0]

just swap the ac pump over for another . the clutch packs on them pack up short out etc .

easy job to swap over then regas.

also check if the front aux fan is running when the ac is turned on ,

common fail is the fan resistor mounted in front of the fan.

Fan spins up fine, A/C is still running cold at the moment (hasn't blown the fuse.. yet)

If the system is charged. It is against the law to release the gas.. $10,000 max fine if you get caught. You must get it degased by a licenced repairer. Just get them to recheck it for you and give you a price on fixing it. If they said it was fixed properly before.. tell them its not... and get them to sort it

Cheers glenn, I wasn't planning on replacing the compressor myself, if I do I'll make sure I get it degassed properly