no backup lights

[mentalQtip]

Hey guys. '74 thing. Been in the garage for three years without doing anything with it. It was stripped when I got it and I know not very much about what to do with it. However;
I finally got most of the lights to work by cleaning all of the sockets and the bulbs bases. I still can't get the backup and brake lights to work at all.(still can't get the brake lines bled either).
I just got a backup lights harness from the pickandpull and installed it I think correctly. No go still.

Any thoughts as to a sequence of things to check? I thought of the switch on the transmission but what should I do to check if it is working?


Thanks

Joseph

[Stray Catalyst]

If neither set of lights is working, the first place you should check is the grounds - VW lights are famous for that problem. Use a test light to check to see if you have voltage in the right places.

Stray

[mentalQtip]

Well damn. After checking everything for continuity and then again, I finally end where I should have started, the sockets. I had to wire brush them more than I would have believed to get them working, but now they work great.

Next is the brake lights. They don't work either.

Thanks to all. A bunch.

Joseph

[Kubelmann]

Most often the infamous brown wire is in on the problem here. Brown wires on all German cars are the ground wire. Clean all connections especially ground wires. Each light has its own ground. Clean all sockets and replace old bulbs. Although most still have a good filament asn appear to be good. After decades of bouncing down the road the end contact is offend worn down and this can prevent a solid electrical connection. I recently restored a 74 with 34K original miles and ended up replaced all the bulbs ($50 at the FLAPS) with new Oshram units. This action alone solved numerous non working lights. In the end only the license plate light needed to have its ground cleaned and the horn had a broken contact on the steering wheel contact switch.