How to test if Auxiliary fan is bad?

[BomberNZ]

Originally Posted by rph74

Is there a quick and easy test to see if the Auxiliary fan itself has gone bad? I checked and the fuse is fine.

The Aux. fan does not turn on when the AC is on. I probably shouldn't make such a big deal out of it, since my AC is still cool when stopped (most of the time). But I want my X5 running perfectly, and I don't want to spend $415 and a few hours of my time replacing the Auxiliary fan only to find out it was something else simple.

Thanks,

Chris

these cant be tested by hooking up to a battery - they have a special "command" signal from ECU to turn on - 30/60/90% etc

these can be tested by good OBD2 code scanners

[wpoll]

Originally Posted by BomberNZ

these cant be tested by hooking up to a battery - they have a special "command" signal from ECU to turn on - 30/60/90% etc

these can be tested by good OBD2 code scanners

Yep - like INPA on a laptop. I use INPA to check my fan occasionally - usually when I do an oil service and I run a few other checks at the same time (reads errors and info. etc.).

[Scott ZHP]

Originally Posted by BomberNZ

these cant be tested by hooking up to a battery - they have a special "command" signal from ECU to turn on - 30/60/90% etc

these can be tested by good OBD2 code scanners

They can also be tested by removing the connector in coolant temp sensor switch in the lower rad hose and inserting a jumper.

[ssx5]

Originally Posted by wpoll

Yep - like INPA on a laptop. I use INPA to check my fan occasionally - usually when I do an oil service and I run a few other checks at the same time (reads errors and info. etc.).

Hey wpoll.. can you eloberate on this procedure? Mine broke the second time in 2 years. Searched several sites with no success. Really appreciate if you could.
Thank yo in advance

[wpoll]

Originally Posted by ssx5

Hey wpoll.. can you eloberate on this procedure? Mine broke the second time in 2 years. Searched several sites with no success. Really appreciate if you could.
Thank yo in advance

Sure thing - there's a menu in INPA once you are connected to the DME (DDE in my case) called "Activate" - usually F6 - then you can use the F1 and F2 keys to turn the fan on and off again. It's a little slow to respond, so turn it on, give a second or two to start spinning, then leave it for 15-30 seconds to get up to full speed and stabilise, then turn it off. Al the this is with the ignition on but the engine not running. Watch your battery levels and don't leave the car or fan turned on too long, as this electrical state may deplete your battery in 10-15 mins (or less!).

[NZBM]

Quick and easy way to test whether the aux fan is dead or not-

Unplug the A/C high pressure switch.
Start the car with the A/C switched on, the Aux fan should run full noise (fail safe) straight away.

If it does not - time for new Aux fan.

[ssx5]

Originally Posted by wpoll

Sure thing - there's a menu in INPA once you are connected to the DME (DDE in my case) called "Activate" - usually F6 - then you can use the F1 and F2 keys to turn the fan on and off again. It's a little slow to respond, so turn it on, give a second or two to start spinning, then leave it for 15-30 seconds to get up to full speed and stabilise, then turn it off. Al the this is with the ignition on but the engine not running. Watch your battery levels and don't leave the car or fan turned on too long, as this electrical state may deplete your battery in 10-15 mins (or less!).

Now i have to research on INPA Because i don't have it nor i have seen it.
Thanks anyways wpoll .

[ssx5]

Originally Posted by NZBM

Quick and easy way to test whether the aux fan is dead or not-

Unplug the A/C high pressure switch.
Start the car with the A/C switched on, the Aux fan should run full noise (fail safe) straight away.

If it does not - time for new Aux fan.

I have two fans that don't work. I replaced when it won't work without diagnosing the problem. Now i want test before i decide to buy a new one.

BTW ..NZBM can you please point me to the location of the A/C high pressure switch.

I will search for it too

Thanks

[NZBM]

Originally Posted by ssx5

I have two fans that don't work. I replaced when it won't work without diagnosing the problem. Now i want test before i decide to buy a new one.

BTW ..NZBM can you please point me to the location of the A/C high pressure switch.

I will search for it too

Thanks

Its on the aluminium A/C Pipe that's clipped to the chassis rail- very close to the lower radiator hose.