Just popped out in the MK3, whilst driving along - full beams on, they suddenly got very dull, at first I thought the alternator had thrown its belt, until a few seconds later when I noticed the smoke poring out of the dash. I pulled over and switched off, - and thankfully the smoke stopped, as I had no tools in the car to disconnect the battery. (Im guessing the issue is ignition switched) I dropped the fuse box, and found this. (sorry for poor pics, Iphone is all i had) the last pic shows the live feed out of the fusebox that goes up to the relay block in the second pic - I've unclipped the connector. which should hopefully stop any fires for now. with the feed disconnected and the relay removed all the electronics on the car appear to work except dipped beam, - full beam works fine. does anyone know what this relay is for? or any ideas why this would happen? I wouldnt usually ask, but I dont have any of my wiring diagrams with me, and am off on holiday in the morning. thanks in advance for your advice. the car is a N reg MK3 GTI 8v. ps - the headlights were replaced last year with non gti H4 type ones, could this be the cause? oh and it doesnt have foglights. thanks again Martin.
very odd, does the abs still work? I cant see any mention of a relay controlling the main beams on a mk3 golf, but looking at the black/white wire it might well be the case. what lights does it have on there actually? does the main beam light on the dash come on when you pull the stalk towards you? that melted wire does it come from plug J, and if so do you think you could say which pin it is? see my fusebox faq for better pics. it might be from pin 3, if so i see on some models this goes to the DRM relay... I'll see if i can dig out more information
got it! seems it was fitted to models with headlight range control, mentions 'town driving lights great britain' as well! wiring diagram edit: from what i can see all the relay does is put extra power into the dipped beam circuit, it doesn't actually power it. without the relay the dipped beam should still get power from the flasher switch as per bog std mk3 golf. ah but if the reason for the wire failure is the dim dip resistor, its possible it has also taken out the dim dip wire to the flasher switch, as they all seem to be joined together when the relay is fitted... its on the front near the driver side somewhere. its about the size of a packet of polos with a yellow wire out of each end.
Martin, Changing the headlights might be tied into this problem; the SE/Gti/Vr type, with two seperate H1 bulbs each, have the dipped filaments lit whenever the headlights are On*, while the basic H4 lights need to turn the dipped filaments Off while the main ones are in use, to prevent overheating the bulbs. I thought that supplying the dipped filaments was the function of that relay; it snaps on when the headlamp switch and ignition are On. My own car with H1 lights and the relay doesn't have a yellow (dip beam) wire in the steering column harness. Re. your pictures - I think the single wire in the last photo is the output of the relay, feeding into the fusebox via the steering column harness. In an H4 light equipped car, it would be the dipped-beam feed from the dip switch. * failing to do so (if the dipped lamps go out when the column switch is switched to main) causes an Mot failure, apparently. People who've changed from basic to Gti headlights usually end up adding a brass jumper plug in the fusebox to power the dip beams. I've saved a couple of the extra harnesses with the relay, if you need to replace that one.
