Q: I have replaced the wiring loom in drivers door last year and all was working fine until today. All of my electric windows and sunroof have stopped working. I have checked fuses and they are all ok? I need to know which relay operates the windows as I think this may be the problem? Can anyone help please?
A: If you have 4 windows, then you have TWO relays. It is rare that two relays would fail at the same time. I have the wiring digram for the 306. The front windows AND sunroof are on fuse 29. The relay is a small plastic box, with 4 prongs labeled 1-2-3-5. Prong #2 is the ground for both relays. The rear windows are on fuse 10. Both fuses are 30 amperes. ((DO NOT be mislead by information on the 306 gti-6 speed car, which has a different wiring, different fusebox, and heated seats connected to the rear windows on fuse #14, plus window/sunroof fuses 16 and 28)) Both YOUR 306 fuses get their power from 12 volt line "G", and the 12 volts from G go to prong #3 on the relay. Can you use a voltage testor to test for 12 volts in the slot for Prong #3? Line "G" also powers your radiator cooling fans and turn indicators (but other fuses for these things) Do they work well? Your front windows + sunroof have a grounding point that is different from the rear window ground point. I see now, that BOTH relays also receive power from 12 volt line "D". This line "D" gives 12 volts directly to prong #1 on the relay. Try to see if there is 12 volts THERE = prong #1. The only other things powered by Line "D" are the brake lights, clock, and 'outside temperature, map reading lamps, and door contacts? Are these working?