Got home tonight in the dark, and found that my reversing lights have gone intermittent (didn't come on when I went into reverse, came on briefly with some gas to go backwards, and then went off again halfway through reversing). I'm guessing this is possibly the common switch problem and I've read that it's probably a DIY job, but does anyone have a picture of where the switch is? Or a description of whereabouts on the gearbox I should be looking, i.e. on top under the battery, or on the side, or what? I'm tempted to have a quick go at it tomorrow but would need to have a good idea of where I'm looking to give me enough time to get down to TPS before they close at lunchtime if necessary.

Cheers!

It's under the battery tray, but you may get to it from underneath, with the engine tray removed. From the top, look for the selector linkage that the gear change cables attach to. The switch is about 8 inches down from that to the right looking from the front of the car, just below the linkage lock lever for cable adjustment.

So basically it's on the passenger side of the gearbox below the battery tray.

Nice one, thanks. Might well do the gearstick cable adjustment while I'm there as well, first is a little bit difficult to get sometimes and doing it on my Leon sharped things up a little bit. Is it possible to get to the switch from the top at all? I don't have a jack and stands at my house so I'd have to pop round to my parents for that, whereas if I can do it from the top I can probably do it on my own driveway with the battery out.

Doable by removing battery Cable adjustment is a good idea as well, they do stretch a bit over time.

Awesome. Aftermarket headunit with no security code so I'll have no problems there, I'll try and get the battery off in the morning and have a crack. I wanted to do the gearbox linkage adjustment as soon as I got the car, but with the smaller engine bay it didn't seem possible without removing the battery (it's easier on the Leon, you can just about get your hands in with everything in place if you're fairly flexible) so apathy stopped play!

Just to add (and not really that relevant) but if you have VAGCOM or ask someone to scan the car at any time, disconnect the head unit before connecting the VAGCOM lead. Some after market head units, send battery level 12V down the K1 line, and it will kill a VAGCOM lead in short or order if the fuse doesn't blow. Applies to OBD readers as well.

I've got a genuine VCDS lead (the KEY-USB) which as I understand it has built-in K-line protection for aftermarket head units. I've definitely never had a problem with any of the cars I've scanned with it, whether it's mine or friends'. Never tried any generic OBD2 stuff though as I have no need to with having the proper lead.

edit - sorry, I missed your part about the fuse not blowing. Is it common for the protection to fail?

edit 2 - "Our other interfaces use output drivers that are thermally protected against shorts. They don't need a fuse. If you plug them into a car with the K-line shorted to +12, they simply won't work in that car, but it won't hurt them either." so I'm reading from that that my KEY-USB is safe, the worst that would happen is that it wouldn't work

Edited 17 June, 201115 yr by gavinchappell

Cool, just mentioned it to be safe

Just to add (and not really that relevant) but if you have VAGCOM or ask someone to scan the car at any time, disconnect the head unit before connecting the VAGCOM lead. Some after market head units, send battery level 12V down the K1 line, and it will kill a VAGCOM lead in short or order if the fuse doesn't blow. Applies to OBD readers as well.

This is why I put in my post to cut and seal the wire for this PIN 8d/3

http://briskoda.net/forums/topic/196288-oem-wiring-loom-colours-pins-for-stereos/