Registration & boot lights

[warby]

I have a 2000 TDI saloon on which I have a problem with the boot light and the registration number lights - they won't come on. I've looked at them and there appears to be power but my knowledge of car electrics is limited. At the last service the garage did say that it may be a problem with my tow bar electrics and I have been having problems with the auxiliary socket. I seem to think that there may be a problem with the earth. Has any one any ideas what the problem may be and how to fix it?

Thanks

[martin1810]

I doubt this is to do with the towbar as a towbar doesn't hook into the reg lights or boot light. If you have power to the reg light run a wire from the other side to a good earth. If the lights come on you know it's an earth fault. Have a look where the wires come out of the boot lid back to the body. This is where wires most often get damaged.

[warby]

Martin thanks for the advice. I have checked the wiring and it appears that it is a bad earth. The earth was live and thought the problem may be the boot light switch. I found some corrosion on the connection so I thought I would try replacing the switch and see if it corrects the problem.