aux fan and AC

[daveking]

Hi all
Is there any way to fire up the ac with no aux fan.
My origil fan blew the 60 amp fuse and on replacement of the fuse the fan
did not work.
Got a known working fan and all it done was spin at full speed.
Ac still did not work.
Smashed the fan to bits in temper.
It was fully gased up.
Put power to the compressor it engaged but still no ac.


Any ideas.


Thank you.


dave king

[Masospaghetti]

I assume the AC will still work without the aux fan. It just won't cool as well at low speeds. I would limit this kind of usage to troubleshooting though.


Edit: Ignore me, apparently I am wrong about this

[workingonit]

Originally Posted by Masospaghetti

I assume the AC will still work without the aux fan. It just won't cool as well at low speeds. I would limit this kind of usage to troubleshooting though.

No, it won't. My Aux fan quit working and so did the A/C. Replaced the fan, and it worked again. There are tons of posts saying the same thing in all the X5 forums.

I would guess that the DME will not allow the compressor to run unless it senses the Aux fan running (in order to prevent overheating).

[andrewwynn]

It's not for cooling the engine it's for cooling the condenser.

On start up the car sends a pulse off power to the aux fan to make sure it's there and won't let ac engage if no fan.

You can however activate the ac compressor with no fan with the right scanner. I did that for a week or two until i got my new fan

[workingonit]

Originally Posted by andrewwynn

It's not for cooling the engine it's for cooling the condenser....

I knew that was the primary function, but I thought I had read that the Aux fan was ALSO supposed to come on at higher coolant temperatures, even if the HVAC wasn't activated.

[andrewwynn]

A lot of cars will have a modified fan program when AC is on for the exact reason you are thinking. Help keep the coolant temp lower with the uncreased load. However compared to the heat being dumped by the radiator i think the extra load from AC almost rounds to zero.

[wpoll]

Originally Posted by workingonit

I knew that was the primary function, but I thought I had read that the Aux fan was ALSO supposed to come on at higher coolant temperatures, even if the HVAC wasn't activated.

I believe this is correct.

I also understand that on some models of e53, the "aux" fan is the ONLY fan....

[X5chemist]

Mine had a bad pressure sensor. The A/C would be cold right away if the engine was hot. Until the engine was hot, the A/C wouldn't cool right away. I would get moving as fast as possible for A/C cooling. I finally swapped out the pressure sensor. A/C now starts to cool right away