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Old 02-02-2009, 01:54 AM
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bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
Join Date: Mar 2008
Posts: 25,236
Mein Auto: 02 BMW 525i M54 auto 130K
Here are the steps I should have used to remove and replace my FSU

As always, I took pictures but here are the text steps I recommend for removing and replacing the 2002 E39 FSU.

0. Get a flashlight, a #2 Philips screwdriver + a set of 6-inch needlenose pliars
1. Move the passenger seat back & lay the backrest down as far as it will go
2. Lie on your back, hands above your head, ready to work in the foot well
3. Remove the #2 Philips screw holding the passenger left-food kick panel
4. Slide this kick panel straight back (toward the rear of the car) to unclip
5. Slide the underside of the glove box straight back (two clips, no screws)
6. Locate the FSU harness connector and put your pliars on the two "ears"
7. PUSH (this is the important part) a millimeter or less inward, & then unclip
(Note: Step 7 took me all of the Superbowl & even then I broke a clip ear!)
8. Once the FSU connector is off, push on the one FSU connector to release
9. Pull out the old FSU and measure resistance from each terminal to the aluminum fins
10. Measure the resistance of the new FSU's terminals to the aluminum fins
11. As they say, assembly is the reverse of disassembly
12. Test the A/C & air & especially listen for fans after the key is pulled out

#4 #5
#1 #2 #3

pin 1 OLD: 600 K ohm NEW: 11.2 ohms
pin 2 OLD: 3.02 M ohm NEW: 1.22 M ohm
pin 3 OLD: 2.219 M ohm NEW: 608 K ohm
pin 4 OLD: 2.136 M ohm NEW: 602 K ohm
pin 5 OLD: 3.05 M ohm NEW: 1.277 M ohm
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Please read the suggested threads and add value, either by pictures or by descriptions, so the next person stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need

Last edited by bluebee; 02-04-2009 at 10:05 AM.
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