window woes

Audi Nut Joined: Sep 22, 2008 Posts: 54 Location: hereford

moring all

when the car is sat in the sun and gets hot the windows stop working when the car cools down they work again Confused

been told this could be the thermal fuse playing up whatever that is anyone got an idea where this part lives, its not in the fuse box stuck my head in there last night.

Posted: Fri May 08, 2009 9:41 am

It could be either the thermal fuse, or more likely a dry solder joint on the main relay itself.
Relay is usually the culprit, heat warms up the inside of the relay and the bad joint slightly opens up enough to lose contact.
I've come across both, was the thermal fuse in mine, but my bro's was the relay.
Also had a look in a duff relay for Clivey last weekend, pointed out a duff joint on that too.

Might as well copy and paste a thread I had on S2forum about this. Useful info for others and I'll link it into this forums FAQ sticky.

....................................................................................................

NOTE, not all relay are the same. Yours MAY be different to the version from a 1995 S2 shown below.
Others do however, seem to exhibit the same dry solder joints.

Location of relay and thermal fuse;

Drop the drivers parcel tray down (4 x M8 bolts) and look up at the top righthand side and you'll see the large control relay. Sitting underneath is three thermal fuses. The ones on the right are in a double holder and for something else (not sure what) and the one for our window/sunroof system is on the left. This is a RHD picture though, I'm not sure how much different LHD is in it's layout.

Red arrow = control relay
White arrow = thermal fuse;

Thermal Fuse;

I've had a gremlin with my windows and sunroof for at least a couple of years now.
At first, well for the first 18 months or so, this was very very intermittent.

The problem effected both windows and the sunroof at the same time. They would just cease to work at random intervals. The windows would cease to work along with the sunroof, the switch lights would be out, confirming no current to the switches was being supplied along with some probing with a DMM.
For the last six months they have been getting worse, switching off a regular intervals for no apparent reason. That is until the last two months ago when I've noticed this problem is temperature related. The warmer the weather, the warmer the inside of the cabin and the more frequent the windows and roof ceased to work.

Now initially after doing lots of thread reading, all posts pointed at the power window/sunroof relay. I replaced that with no less than four others, all good working examples. They ain't cheap either, even secondhand.
As they all ceased to function together at once, and both front windows along with the sunroof worked brilliantly when actually working, meaning no squealing, no struggling, no grinding noises, both motors free from water ingress, all cables sound, grease in the regulator and on the motors worm drive not old and hard, then they themselves individually weren't the problem.

There's a lot of posts on here that refer to thermal relays, but all state (those I could find anyway) that it's in the large control relay or one on each individual motor.

But there is another, one that effects the whole circuit in general and not just one window or the roof on their own.
I spotted this on the loom I have for the set of opening rears I've not yet got round to fitting. Hmm, I wonder if this could be the little blighter then. Car interior gets hot, ignition on and current flowing through it cause the fuse to trip. Cools down and then power restored?
Got chance to have a look today with help from my bro (I've got a bad back again). Sure enough, turning the ignition on saw the windows work for a couple of minutes, then all power was cut. Dropped the drivers parcel shelf down and easily located the fuse I was looking for, it sits right in front of the large control relay for the windows/sunroof. There's three of them all located in the same place. The one I needed was the one that's located into it's own holder, the other two are in a twin holder and are for another system on the car. Sorry I couldn't grab a picture (not like me I know). It's a 20a fuse, part number 443 937 105. (pic further down)
After replacing with the one from my spare loom, all was sorted.

Today I thought I'd rip the old one open and have a look at it's insides to see how it worked and why it was misbehaving.
Its a simple enough thing, two terminals, one live the other earth go into it. Inside it has a contract breaker type relay strip with a small coil of wire wrapped around it. Putting enough current through the wire will heat the strip up enough for it to bend and lose it's contact.
Indeed, hooking up a simple 9v PP3 battery with a couple of clips was enough the heat up the strip and it lost contact.
Current from the 12v system on the car (no idea of the amperage though) coupled with it already being hot inside it's metal casing, must have been all that was needed to create hell on with my windows.

Ok, I know some will think "So? WTF? that's nowt, an easy fix"

BUT!, when you've spend a daft amount of time chasing the normally mentioned relays, motor faults, cables, power to the switches, dodgy switches and the all the rest, and then it turns out to be a simple fix like this! well! why not post up your findings? Could save someone else time and money. The fuse is only £7 (and even then, I already had one), whereas I've paid over £70 for for four perfectly fine relays.

Contacts closed;

Contacts open after only 30 secs on a 9v battery;

Relay;

Are the power windows and sunroof relays designed to self destruct or what???

My brothers 1995 S2 Coupe has suddenly started with this intermittent problem.
First up was the have a look at the relay, as this is the most common area of hassle.

Removed it, exact same version mine had.
Siemens manufactured, Audi part number 4A0 959 257 which has now been superceded to 443 959 257B if you buy a brand new one from Audi.
Siemens part number 79FA404 and has 363 on the top.

His was the relay that was at fault. A cracked solder joint.
Me being me, I thought I'd take some pictures of it. It's all good a well reading about stuff, but pictures paint a thousand words wave

Before those pictures, if your relay is dead for good, they are quite expensive new. Try in the region of £70 inc VAT Rolling eyes

There's always a cheaper alternative though (less than half the price), they are available on the bay of fleas.
Not re-manufactured, but genuine Siemens relays, just not direct from Audi.
"Exactly" the same relay, in the same case with exactly the same internals down the the exact same components.
I've got one of these in mine, been in there for a good while. I never got round to swapping the original back in. Was sick to death of relay swapping before I fixed it with a new thermal fuse.
Link to relay >>>> HERE

The dead solder joint;

Blown up;

From the other side;

Blown up again;

Audi Nut Joined: Sep 22, 2008 Posts: 54 Location: hereford

fantastic

will play tonight

Posted: Fri Oct 23, 2009 1:06 pm

This has just proved most useful to me.

Yesterday my windows and sunroof stopped working so I looked on Audifans for a solution and came across this thread.

Today the windows still weren't working so I followed the above.
I couldn't see anything wrong with the thermal fuse and after leaving the ignition on for a while and watching the contacts I could see that they werent parting nad a current was passing throught he fuse uniterupted.

I removed the relay and opened it up but it is nothing like the one in the pics above. There is no circuit board in it but a reel of copper wire and a braided copper wire to the contacts.
Reassembled the relay and put it back in its holder and hey presto the windows and sunroof started working.
I dont know what I've done to change things but its thanks to this thread and the O.P taking the time to write it up and take pics that I was pointed in the right direction to solve the problem.

Thanks Nathan

EDIT

Rereading the above I can see that I looked at a totally different relay numbered 217 I think.

Posted: Tue Aug 31, 2010 11:01 am

Hi.
I have a similar problem , My passenger window and sunroof are working fine. But when I try to open the drivers window i'm just getting a click from the Relay under the dash. Is this a faulty relay ?
Thanks.
( Audi coupe ).

Newbie Joined: Feb 04, 2011 Posts: 11

Pastit,

I have exactly the same problem - did you resolve yours in the end? If so, what was the solution, if you don't mind me asking.

Cheers,

Jim

Newbie Joined: Sep 03, 2011 Posts: 4

Hey Guys,
Just looked under my steering wheel and its a mess!
There aint a 363 but a large relay the same size, Would it be the same one?
And I only have one thermal fuse but its exposed with no cover.
Any help would be appreciated
Cheers

Site Moderator Joined: Jan 31, 2003 Posts: 9144

363 isn't the part number so isn't definitive.

There were several types of that relay over the years

Newbie Joined: Sep 03, 2011 Posts: 4

Cheers Mikes2, I have ordered the Relay that is suggested above and on VW/Audi Elsa for my vehicle as well as the Thermal Fuse so by Thursday should have it working again.
Cheers All

Newbie Joined: Sep 07, 2011 Posts: 5

The ones on the right are in a double holder and for something else (not sure what) and the one for our window/sunroof system is on the left. This is a RHD picture though, I'm not sure how much different LHD is in it's layout I removed the relay and opened it up but it is nothing like the one in the pics above. There is no circuit board in it but a reel of copper wire and a braided copper wire to the contacts.

Site Moderator Joined: Jan 31, 2003 Posts: 9144

Ordered from where ?

Did you get a price before ordering ?

That relay is expensive - last price I saw was 3 figures

Newbie Joined: Sep 03, 2011 Posts: 4

The 363 mentioned above, i ordered off Vw dealer where i live, I got it for cost, at £7 and odd pence, the Thermal fuse ordered from the same place was £9.77 retail.
Both are being delivered tomorrow so after work i "should" have windows and sunroof working again.

Site Moderator Joined: Jan 31, 2003 Posts: 9144

bit of a bargain. hope it sorts the faults

Newbie Joined: Sep 03, 2011 Posts: 4

LOL Went down to pick the bits up today!
The numpty parts man ordered the thermal fuse on saturday, not the relay. Then on Tuesday the fuse was ordered again.
The fuse was £9.77 (but i got it at cost so was £7).
I asked how much the correct relay was from a more senior parts man and it was £170
Really hope when the rain stops that the thermal fuse fixes it. Don't like the thought of paying for a relay.
Cheers to Audifans.net for the help

Newbie Joined: Jan 21, 2012 Posts: 9 Location: Ireland

Hi All
I have the same problem with my drivers side window as mentioned by Pastit above. Passengers side working fine and switch for drivers side seems to be working also. The Thermal fuse seems to be working as it allows passenger side to operate. There is a clicking sound coming from the relay box when I try drivers side, does this indicate that this component needs replacing? Any help would be appreciated.
1994 coupe 16v

Posted: Wed Feb 06, 2013 5:53 pm

Hi.
My drivers window started working on its own for about 3 weeks , then stopped working again. I dont even get any clicking or anything anymore. So I just don't use the drivers window.