DIY- Comfort Relay Repair/ Power Window - Sunroof issue fix

[Seeker]

EDIT- THIS APPLIES TO 92-93 production cars ONLY!!




OK... So I had the problem where my power windows and sunroof both would not function on my 1993 325i.

The problem started as an intermittant issue.. but this winter with extreme cold temps, the problem became permanent.

All my power windows and sunroof BOTH would not function no matter what I did.

I suspected the problem was with my Comfort Relay. Simply by looking over the wiring diagram in my Bentley manual on page ele-233.


I did a search and found this gem of a fix..

http://forums.bimmerforums.com/forum...13&postcount=3

He wrote:

I had problems with my comfort relay too, if all the windows and sunroof dont operate it is a strong possibilty that this relay is at fault.On UK spec cars its is located under the glove box(L/H side of car) i believe it is located under the steering wheel trim on cars across the pond, it is a blue relay(about an inch sqaure) remove it and take the cover off, on the bottom of the circuit board you will see a track with a few soldered pins in it, there will be one in the centre(center for you guys) and it will probably have a crack running aroung it(dry joint) put a blob of solder on this and all should be ok, new ones cost about £15($25) but will eventually go again so you are better off repairing it, only takes about 20 minutes to do the whole job

This dude was ON TARGET with my problem... I took my relay out and sure enough, that solder point was broken. It took me about 20 minutes to fix.

I'll share w/ pics what I did to fix it:



Tools needed:

Phillips Screwdriver
Small Jewlers straight blade screwdriver (something to pry the relay open)
Drop Light
10mm socket/ratchet
small pliers
Soldering Iron/Solder

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[Seeker]

First take the lower dash panel off.. should be two or three small phillips head screws. Unclip the chime connectors and set the panel to one side.

You should now see this knee bolster. Using an extention w/10mm socket on the end, remove the three bolts securing it in place. Make note about a small bracket on the right side behind the bolster... it acts like a washer of some sort and goes between the bolster and where the bolt threads in... the half circle part of it cut out goes to the bottom of the bolster towards the front and is shaped to rest up against it.


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[Seeker]

Once you get that knee bolster off, then you can easily access the Comfort relay.
It's the blue one I'm pointing at in the pic. It's inside a small harness that is held up by two tabs on the left and right.

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[Seeker]

To drop the harness down to access the relay, there are two fat tabs on the left and right. Just gently push them outwards away from the relays and the harness will release/drop.

[Seeker]

To remove the relay from it's socket, there are disengagment tabs on the back sides. You squeeze them in to release the relay from the socket.



and FYI.. if you have gotten this far, you can jumper the terminals on that socket to directly power your windows or sunroof!
look at the pic below and you see some #'s next to the terminals where the relay plugs it's blades into.

#4 is 12v Hot at all times.. you can verify that with a simple 12v test light.
if you jumper #4 to #2, you will be able to operate your windows.. if you jumper #4 to #5, you will be able to operate the sunroof
That way you can get your windows shut or down or whatever while you fix the relay.
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[Seeker]

Now take the relay to a workbench.

This pic shows the relay and on the side edges between the blue plastic and the black plastic w/pins sticking out, you will notice a thin slot on each side.

In this pic the slots are on the left and right side. What you need to do is fit a tiny screwdriver or other prying device into the slot and carefully disengage the snap fit connection that holds the blue plastic cap over the relay guts/bottom pin board. (careful not to slip and gouge your hand!!)

I already had the relay in this pic disengaged, but took a pic of it for illustration purposes.

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[Seeker]

Gently slide out the relay guts and pinboard... it will all come out together.

Make note that the tiny circuit board slides back in a slot inside the blue cap.

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[Seeker]

Now we can find the problem!!!


In this pic, if you look directly into the center of the circuit board and slightly to the left, you will see a solder joint that has corroded/cracked. The connection to that component has been severed and the relay can no longer function.

[Seeker]

Here I show a fuzzy pic of a soldering iron and solder wire ready to resolder that bad connection together.

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[Seeker]

I put about 4x as much solder that was actually necessary. But I wanted to be sure I got it good.

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[Seeker]

Now just put the relay's blue cap back on and the whole relay back in it's socket.

Go ahead and test it with the key in the ignition to first position prior to putting your underdash parts back in.

Mine immediatly started working again!

Put the everything back together in reverse order.
Dont forget to put that spacer back in behind the knee bolster and reconnect the chime on the underdash panel... i forgot to reconnect mine and had to take it back apart

Not only did I save myself about $20. I also saved myself the time waiting for that $20 part to arrive... and it only took me about 20 minutes to do the entire job.





And as that guy that gave me the clue to fix this.. evidently all of these series of relays of this brand are prone to this failure.. must have been a production defect. Imagine some of the new replacements of different mfr wont do this, but why buy a new one when the original just needs this simple fix?


Hope this was helpful.. I'm sure happy about it!

[Doug001]

Nice DIY

Thanks, Seeker!

[elton123]

BMW owners are more technically knowledged than your average car owner, good writeup!

[Daved]

Good work!

Just for the record, the comfort relay gives power to the windows only on earlier cars with ZVM.

[Seeker]

Good work!

Just for the record, the comfort relay gives power to the windows only on earlier cars with ZVM.

Yea... think it's only tied in for both windows/sunroof for 92-93 sedans only.


It's crucial to check the wiring diagram for your specific vehicle... ti's/coupes/verts are all different setups than my sedan.


This writeup was for 92-93 sedans ONLY.. but may be worth a look into if you have a relay just like this one that you suspect is faulty on other versions of E36.

[Zaks]

haha, you mean 10x more solder... good job with the DIY though

[tmoney662]

I had the EXACT same problem on the EXACT same solder point..!
I fixed it as well with a blob of solder, works fine now...Nice write up, this is a common problem--

[johnwoo]

THANK YOU!!!!!!!! worked fine for me

[Tamad]

Q?: will this work for me...

after changing batt/alternator AUTOMATIC closure Did not work...ie when leave the windows down/open sunroof..THEN, when you armed the alarm it should close aswell togerther with alarm..mines not workin anymore after doing batt/alternator change...theres is no direct ans to my q?

do this...do that...this and that...that and that..
(only sunroof is not workin w/ automatic closure security)
wot seems to be the prob?

[bradfish]

now dont know if this is the same but my comfort relay is in the middle of a black relay and orange is that in the right place

[Lurch 318is]

its hard to tell exactly which connection you soldered... can anybody please possibly point it out in a photo, i would greatly appreciate it...

[jmejiaa]

Just check them all, wiggle it a lil and see if any are disconnected. I did mine and there were like 3 that were bad.

[cm325]

I,ve had this problem with my 92 325 for about 5 yrs this is awesome im going to check as soon as i get home and get to it in the garage. it was one of those things i just never took the time to find especially since it didnt affect the door locks or performance. thanks for the post i hope i have the same results

[cm325]

as soon as i got home last night i kissed my girls said hello and was off to the garage.this was an awesome thread. i've spent so much time worrying about how much it would cost to get it fixed than it actually took me to do this i spent more time waiting for the iron to heat up enough to do the joint. great job "sneeker" cm

[jijacob]

its hard to tell exactly which connection you soldered... can anybody please possibly point it out in a photo, i would greatly appreciate it...

The one with flex all around it?