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**Due to the large amounts of PM's I get over this, please first check your windows/sunroof relay for cracked soldering joints. You can see pictures of this further down this thread. It's a cheap no cost fix if they have cracked. If not, carry on reading**
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
(edit, after some more searching today I've come across a couple of posts noting these thermal relay / fuses)
Contacts closed;
Contacts open after only 30 secs on a 9v battery;
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
(edit, after some more searching today I've come across a couple of posts noting these thermal relay / fuses)
Contacts closed;
Contacts open after only 30 secs on a 9v battery;
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