Good afternoon all who spend their weekends fighting Mk1 Fabias' quests to join the scrapheap. As this information does not seem to be clearly available on the internet (only scattered hints) I thought I would write it down and share it. As I'm sure many of you know, the facelift MK1 Fabias and I believe also the pre facelift Mk2s (and 9N Polos, early Roomsters and T5s must have the same problems if they have the same modules) have electric window drive modules that get to a certain age, then only work intermittently. Typically, they work when the battery has first been connected, and then stop working about 5 minutes later. If you reseat the fuses it seems to reset them and then they may or may not work again for another few minutes. When this happens, you then go on a wild goose chase, starting off thinking it is a battery voltage problem, then maybe a switch problem, then maybe a wiring problem in the door, or maybe even a comfort control module problem (gasp!). You also think maybe the module has failed and look on the internet and see whatever extortionate price is currently being charged for a probably also faulty second hand replacement. For reference, my car is a facelift mk1 Fabia, registered in March 2007. The window modules have mfg dates in February 2007. I am 99% certain the cause of this is faulty capacitors in the electric window modules - 1% uncertainty in case there has been a freak accident I am unaware of causing mine to work again. To open a module, there are no screws, you just need to find some thin tools to use as wedges. I used a screwdriver or plastic trim tool to lift each clip and then an ice lolly stick I cut down to keep them wedged open while I did the next one. When all clips are wedged open you pull the two halves apart. One side contains the motor and power contacts for it, the other the electronics that read the switches, communicate with the other modules, and drive the motor. You can remove some more of the plastic around the connector sockets but it is a bit fiddly. The electronics side is where the problem is. Next to a big plate shunt resistor thing, there is a single electrolytic capacitor, that probably has green stuff on top where it has failed and vented. The negative side faces he nearer edge of the board, away from the switch connectors. This is probably the only component other than the relay that is feasible to replace if it goes wrong, those being the only two components that are actually labelled with what their values are supposed to be, and the only ones big enough not to need micro soldering equipment and skill. Being an electrolytic cap this is probably the only one liable to fail with age, thankfully. The original cap is a 35V 100 microfarad part, specifically the epcos B41851 (which I think I found you can still buy), though any 100 uF cap with more than 35V tolerance should work fine as a replacement - I used some 50V ones I found fairly cheap. To cut a long story short, I have two modules now in my car (rear are manual in mine thankfully) that work reliably and fully after replacing that capacitor in each. I do not believe the relay needs replacing, as a module just works until it doesn't, then starts again when power is reset, rather than half working all the time in the way you'd expect with a faulty relay. The relay is also an off the shelf part that can be replaced if it is faulty, but it is unlikely that it will be. I will say that it isn't the easiest soldering job in the world, as it seems to require a fairly high power soldering iron to properly melt whatever solder they used. It probably also doesn't help that the cap is connected to the relatively large shunt resistor (the funny shaped metal plate) that soaks up a lot of the heat. I was trying initially with a 25W iron, then later a 40W iron, but I think if you want success, don't repeat my failures and instead use something better like a 60W or higher. It would also probably help not to use a solder sucker with a crack in the nozzle as well. I am aware that Breezy Pete offers a repair service for these modules, and the knowledge that he gets them working by repairing the module was a very useful clue. I thought that this information would be helpful to be out there on the internet regardless for people who like to do board work themselves, and people in other countries. But if you do not like to interfere with electronic components like these modules, or you don't have decent soldering equipment and you don't want to get into it and invest in some, then that repair service is probably still your best option given it can be a bit fiddly and frustrating, and dangerous for the board if you are not well enough equipped. I wanted to try and demystify this though after spending whole days investigating this and enduring the amount of frustration I have over what should be a simple thing. I am not completely sure how the failed capacitor causes this kind of failure. The modules are clearly capable of functioning with a bad capacitor as they do that when they are reset. I seem to remember someone on here measuring wire voltages and finding that some other part of the car cuts power to the module after a few minutes. Perhaps a comfort control module or something like that lets them run for a while, then sees that the module has too high idle power consumption due to the capacitors leaking current, or senses that it is a hazard in some other way, and then cuts power until they are reconnected? I did however manage to make my case into a long story, by initially using old salvaged capacitors I had to hand instead of buying new ones, so that the modules worked only for a day until we replaced them again (my dad did it later on as he is better at soldering). One also detached due to a particularly bad soldering job I did (they are through hole, but I ended up soldering to the old leads as I had a lot of trouble removing the old ones with my poor equipment and skills, and on one directly to lifted traces). At some point during trying to resolder one, I must have damaged something else on the board, because that one doesn't seem to work any more even with the capacitor having good continuity to the other components attached to those pads. So I think my poor soldering skills and persistence with them may have destroyed a module which is really not good. However, we had a backup. My uncle is a car trader and happened to have an 07 Polo he was scrapping. He kindly took the modules off for us, though he didn't think to check if they worked beforehand, assuming they did. This is where it gets confusing. Before any of the cap business, we had tried these Polo modules on the car and found it did not fix the problem. However, I can't remember if it had the same behaviour as before or just didn't work at all. After the cap business, we had to try one of these modules after I presumably broke one of the skoda ones. We replaced the caps and tried the Polo modules, and combinations of Polo and Skoda modules. They did not work properly. After a lot of head scratching and wanting to smash the whole car up with a hammer, one of us realised that we were trying the polo driver side module on the passenger side, and the polo passenger module on the driver side. This happened because the modules are physically the same, but flipped on the Polo vs the Fabia (I suppose someone clever at VAG was asked by their boss to figure out how to create the most possible confusion for DIYers for the least possible investment in new parts) causing each module to only mechanically fit on the opposite side to which it is supposed to run. You'd think this wouldn't make a difference to anything, given the hardware and software numbers written on the electronic parts are all the same on the Fabia and Polo modules on both sides. But there must be some kind of software coding that is aware of what side's window switches it is connected to, because you can have two modules on the wrong sides be completely dead, then connect them on the right sides and they work flawlessly. The solution to this, as the motor part of the modules are the same for each side apart from the output shafts being on opposite sides, is just to remove the electronic parts from the motor parts of the modules using the method detailed earlier, then swap them. After this they work perfectly, even if one side says Skoda and the other VW. Each module is labelled "PDRS" for passenger side, "DDRS" for driver side in the part code. The Polo was a right hand drive UK car as well in case that makes a difference to anything. The Polo modules were made in March and April 2007. I discovered some other window module quirks along the way that can be confusing. If you only have one working module connected at a time, even if it is not faulty, it will not function properly without the other, even if it is the driver module. If i have only the driver module connected, it will work on its own, but the one shot winding will not work, and the window will work even if the keys are not in the ignition and the car is locked. Apparently it gets power for that somehow. As soon as you connect a working passenger module, it immediately snaps back to the proper behaviour, where it works only for a brief period after removing the keys and not when the car is locked. Then when you turn on the ignition again, both modules work and the one shot works too. When you have a working module connected to a non working module, I can't remember if it doesn't work at all or has the same behaviour as one working module connected. I think the passenger module on its own behaved similarly to the driver side on its own. In the end I got it all working, until two weeks ago when I accidentally tried the one shot on the passenger window while it was iced up, and I couldn't stop it before it screwed up the regulator. A job for later in the year I guess. Here is a photo of the original cap of one module: Here is the board on both sides with it removed: Here is my dodgy replacement after I realised the first cap I put in was already bad because I didn't think and then replaced it with a 25V that seemed to be good but only lasted about a day. You can see my poor soldering technique and use of low power soldering iron has led to pads and traces being lifted when previous caps were removed. On the far left of this photo you can see the terminals that insert into the motor half of the module to provide power to it. Behind the capacitor you can see terminals for the switch and (presumably) central control connectors.