Coolant system antics

[80stech]

The fan is has a built in driver and is pulse width modulated so not going to work by putting power to it.

[Oldmactech]

Hmm. Ok. Is there a best way to troubleshoot?


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[Effduration]

Originally Posted by Oldmactech

Hmm. Ok. Is there a best way to troubleshoot?

yes...

1. The fan should flicker on start-up
2. The fan should come on with AC..if AC is working
3. I am told if you unplug coolant temp sensor on lower Radiator hose it will come on when you turn the key ...I haven't tried it.

If the fan fails to turn on in above tests, replace it.

you can also activate it with INPA and other good quality 2-way scan tools.
and of course you can lay any known-good fan from an E46, E39, E83, E53 E36/7
on top of your engine, plug it in to your fan's connection and see if it works.

I like the TYC brand fan for E53 found on Amazon.

[Bdc101]

If you can't get it to run at all, make sure to check fuse F107 behind the glove box.



This is not the fuse that power the fan, according to newtis and the manual. It is the fuse that powers the fan in 2004 and later cars -- however, some 2003 cars appear to have switched over without proper documentation. There are two of us on this forum that have had fuse F107 blow and cause an inexplicable failure of the fan, only to find that fuse F107 was actually powering the fan.



Just throwing that out there if you can't get it to turn on at all when you turn the AC on. (Post #10 here: https://xoutpost.com/bmw-sav-forums/...continues.html)

[Oldmactech]

Thanks.
Last PM I disconnected the lower coolant switch, no fan, shorted the coolant switch, still no fan.

Pulling Fuse F61 this AM before it gets to hot here.

One thing I’m curious about: the two vertical aluminum AC tubes next to the fan connectors get immediately scorching hot. Normal? Any cure for 2nd degree arm burns?

Lastly: mine is an 03’, how do you determine if it’s before or after facelift (I think it’s called ?)

I have a fan on the way. Looks like fun to get to it?


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[Effduration]

Originally Posted by Oldmactech

Thanks.

Lastly: mine is an 03’, how do you determine if it’s before or after facelift (I think it’s called ?)

I have a fan on the way. Looks like fun to get to it?

you have a pre-facelift... '04 model year (sept '03 production) is when facelift started.

I have only replaced fan on a post-facelift E53 which was a couple hours involving loosening/removing the bumper, etc. I think I read the pre-facelift is easier, but not sure...Have a search.

[wpoll]

Originally Posted by Oldmactech

... Lastly: mine is an 03’, how do you determine if it’s before or after facelift (I think it’s called ?) ...

This makes in obvious (and note that, as already stated, production of LCI began in Sept. '03): -



*edit* - NOTE!! LCI began in MY2004 (not '03 as indicated in above image)

[Oldmactech]

Fuse F61- tests good. Waiting for the fan.

Thanks I thought I read in the Bentley that 9/03 was some sort of cutoff but I’ll defer to your knowledge.


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[andrewwynn]

Not a huge fane of crawling on the ground I was able to change my fan out the top. I think I may have cut into some of the plastic ductwork to make It possible.

I do recall some of the bumper cover screws were rustes into the spring nuts and just spun the nut you can't access. I used a small hole saw to cut the plastic around the nut and used a larger head screw on reassembly.

I live in the rust belt your experience may be much less rusty.

[Bdc101]

Wpoll, in the US we did not get the LCI until model year 2004.