how can I confirm power to the fan, which wire should I be testing?

On the fan shroud behind the radiator is a connector with wire leading to the aux fan. Disconnect the connector and use a volt meter to test the two thick wires. One will be power and one will be the ground. The Third skinny wire is the signal from the DME to turn the fan on.

If you don't have 12 volt at any one of the thick wires the 50 amp fuse behind the glove box is most likely blown.

the two terminal of the big wire have 12 v to them. so I think fuse is fine. This doesn't sound good~~

I've had 2 X5's both times it was the fan itself they seem to go bad often as do the window regulars and door handle mechanisms lol have replaced all 4 of those........and the coils too replaced those as well.

what coils are you referring to? the ignition coils? or the AC coils? I am still on my original Fan, window regulators, and coils and I am at 170K miles. So I guess it is time to replace...

If you are getting a fan fault, then the fan is no good. The fan is checked at start by the DME, that is why you may be able to clear the fault, but when you restart the engine, the DME goes and test the fan and come back with the fan fault.

I brought a Behr fan for my X. There are cheaper fans, but I think Behr is an OEM.

Cool! I just ordered Fan yesterday and it is coming today from Ebay made by Behr for $324 Shipped. So to conclude what happend to me and the fixes are:

First my AC was working intermittently and AC is cooler when car is running, all of a sudden while I was in traffic, the expansion tank exploded( I could hear the pop) - I believe this issue is due to a bad condenser fan which is not moving air through the condenser when I am sitting in traffic in 100+ degrees.

Then I replaced almost every piece of cooling system except radiator and belts, then AC is working halfway, weather got cooler, I am driving around and AC is blowing very cold. However, AC is not as cold on passender side, which is still a mystery until I replace the condenser fan. (I ran the bmw 1.4 scanner and it tells me about the Fan Fault)

Today, I am replacing the condenser fan. Hopfully everything will be fixed!

Again, Thanks Upallnight for ongoing support and comments from other members!

When you install the new fan and before putting back on the bumper cover, run a scan and see if the fan fault is gone.

May I ask a favor (for the forum)? Since you've been around a long time (2005)...and you're still here...it would really be helpful if you'd go ahead and create a signature that included the info highlighted in your quote above.

I came in on the second page and was lost as to what engine/model/model year you had as you wrote of the things you tested and changed etc. It wasn't until I kept surfing backward through the thread that I found your vehicle information in the first post. :p:

Having a permanent signature that includes your vehicle's model/model year/build date info... really helps the forum when either searching for info or coming later into a thread...especially when the discussion turns to things that may be engine/tranny/model year related or a change during mid production. When the forum members has no signature with vehicle information...it can be difficult to either respond or understand what may apply or if the situation is similar to the person searching/reading the thread.

Help us out since it appears you've been around here a while (and hopefully longer, too)...create a signature with your e53 info...that way when old or new members (or even strangers googling info) find any thread you've created or posted in...your vehicle information will always be present and they'll know if your post is relevant to their situation or inquiry. :)

I will do that. Can anyone give me a brief guideline on how to get to my signature.... I am very sorry... I looked for it for over 15 minute and was unsuccessful.... I fixed my car, but I can't find a signature function on a forum...:dunno:

Like you said... this site changed alot... back in 2005 everyone is chatting about what mods to do to their car, some preventive maintenance... nowadays... everyone is focus on fixing their car... I used to love the x5world page which gives index to engine, transmission, electrical, and mod write ups... This forum helped me kept my X from 2004 till now from 0 miles to 170K miles. Anyways... if some of you can give me some pointers.. that would be great!