Set To Recharge AC, Help With Facts

[razorboy]

OK, updates on my AC repair.

Took the truck to my friend and he pulled down 25hg of vacuum and the system held it no problem so I guess the schraders are fine.

However, he noticed right away that the system was not doing anything. He dumped some R134a into the truck under vacuum but still nothing.

I guess I have a classic X5 problem going on now.
The auxiliary fan does not switch on at all. From what I have read there is some debate over this. Some say their AC systems work without the aux fan while others say the DME will not run the AC system if it does not detect the fan running.

I would like to test the aux fan to see if that truly is the problem but have not read a post yet that details how to bypass the DME and run the fan.

Have also read that 12v supplied to the lead of the AC compressor should allow me to hear the clutch engage and disengage. I guess I can start there but want to verify that it is ok to do that. Would not want to do anything that would risk damaging the computer.

Anyone have a method for testing the aux fan?

Cheers
Bernie

[Rondo]

Hi here are some fan facts you can also activate the fan with Inpa software to test .I would not put dc voltage to the fan as you read in the wds article you need a different power supply [square wave form?]

[razorboy]

Very cool,

Yes, that was why I wasn't attempting to send any voltage to it. I wanted to know if there was a correct way to test it as I knew it had its own onboard PCB.

I believe I can send 12v to the compressor though from what I have read. That would rule out one item.

Thanx!
Bernie

[rph74]

Originally Posted by razorboy

OK, updates on my AC repair.

Took the truck to my friend and he pulled down 25hg of vacuum and the system held it no problem so I guess the schraders are fine.

However, he noticed right away that the system was not doing anything. He dumped some R134a into the truck under vacuum but still nothing.

I guess I have a classic X5 problem going on now.
The auxiliary fan does not switch on at all. From what I have read there is some debate over this. Some say their AC systems work without the aux fan while others say the DME will not run the AC system if it does not detect the fan running.

I would like to test the aux fan to see if that truly is the problem but have not read a post yet that details how to bypass the DME and run the fan.

Have also read that 12v supplied to the lead of the AC compressor should allow me to hear the clutch engage and disengage. I guess I can start there but want to verify that it is ok to do that. Would not want to do anything that would risk damaging the computer.

Anyone have a method for testing the aux fan?

Cheers
Bernie

FWIW on my 2001, when my Auxiliary Fan died, the A/C still worked. The only problem was that the A/C did not work well at a stop. But the compressor definitely came on, and I had cold air when driving on the highway. As far as testing, sorry, I'm no help.

Chris

[razorboy]

Hey Guys,

Updates today on my AC problem - Turns out it is the Aux Fan.

I took the truck to a shop this morning on a recommendation and they did a great job. For those in the Vegas area, they are called Top Car Service, 980 N. Nellis.

First thing they did was evac and reload the R134a to stock. The AC did not kick in. Then they hooked up the computer to the truck and was able to turn the compressor on and off no problem. The aux fan would not engage no matter what was done so now I know. Total charge for about 45 minutes of working / joking around = 0 dollars. They even knew I was going to replace the fan myself and offered to doublecheck the system once the new fan was installed. How is that for "not-even-a-customer-yet" service?

So as far as replacing this aux fan, there are many options on ebay for various quality and price fans. Looks like a lot of them are probably made in China so I don't place too much trust in those. Can anyone who has a successful swap of this fan let me know what brand you settled on? Definitely will not be paying through the nose for a BMW replacement.

Cheers
Bernie