E34 Aux Fan

[ehoe]

Had my aux fan (aka aircon fan) replaced recently coz it had died on me and could see the engine temp was going up a little during standstill. My previous aux fan (when it was working), I noticed that as long as the aircon is switched on, the fan will be on running on low speed continously. When the temp goes very high then the temp sensor will activate the fan to go high speed but this rarely happens. Anyway with the new aux fan in now, I noticed the fan only comes on occassionally (i.e it switches itself on & off) even with the aircon turned on. Just wondering is this normal and meant to be this way or should it be continously turned on like my old aux fan?. Perhaps my old aux fan was faulthy?? no idea... Hoping some sifu's out there could shed some light on this. Tks.

 

[Iqlima]

http://www.nmia.com/~dgnrg/page_20.htm

follow the link

 

[ehoe]

Originally posted by Iqlima@May 14 2006, 11:57 AM
http://www.nmia.com/~dgnrg/page_20.htm

follow the link

Tks Iglima for the link. Very informative.

The site mentioned that the aux fan should come on when the aircon is turned on which mine does BUT mine also automatically will also switch itself on & off. I'm trying to see a pattern but if I a not mistaken it follows the aircon compressor. Whenever the compressor kicks in, the aux fan turns on and vice versa.

So just wondering is this how its suppose to work or is it suppose to be permanently and continously turned on at low speed as long as the aircon is turned on?.

I suppose it does make sense to have the aux fan switch on and off automatically coz that will extend the life of the fan considerable. And these fans aren't cheap man!.

Anyone know? TIA....

 

[skinhead]

on my e30 the auxfan will turn on and on and on till u switch off the a/c
but on my e34 it will turn on the 1st time ur turn on the a/c and stop when its getting colder, on and off there after.
i guess its depend on the system, imo it shud be on-off operation. my pee turn to ice in my e30.....

 

[ALBundy]

On my e34 its on/off depending on the refreigerant pressure. Mind you, the compressor doesnt run all the time, when the refrigerant pressure is high and cabin temperature has reached the desired setting, the compressor will cut off and hence the fan too!

There are two switches that will activate the aux fan. One is directly connected to the radiator and the other is on the refrigerant piping. Hope this helps

 

[ehoe]

Tks to all for your replies ya.

I guess my aux fan is operating as normal then based on feedback from all. The aux fan will turn on & off based on the aircon compressor. Normally if the compressor is running the fan comes on and vice versa.

The other thing that can activate the fan is the temp switch located on the radiator. When the temp reaches a certain temp, it activates the fan at low speed. If the temp continues to go up and it hits a certain higher temp it activates the fan at high speed. So the aux fan acts as a secondary cooling fan during those really really hot days or when you are stuck in traffic.

So thats what I have found out thus far so just to share with all. Tks again.