E30 Number Plate Light Help

[Forrest 35]

So noticed today for the first time in ages with my car immobile, I turned the lights on with the key in the ignition and the number plate warning light came on, on my check panel.

Checked fuses = fine

Checked bulbs = fine

Checked power at electrical connectors to lights = no power

Checked earths inside boot and on rear seat stay = fine + cleaned up to be sure with sandpaper

Checked power at plug for the rear lights check relay (beside the radio ariel on top of LHS of boot beside shock mount at the points for the associated colors for power for each number plate light (grey + grey/black) according to the wiring diagram = no power

What have I missed? I know it is quite hard to analyse electrical problems without actually being there, just wondered if someone can connect the dots and read the diagram better than I can.

Here is the wiring diagram I am using, everything else works fine, aside from the number plate lights.

http://www.armchair.mb.ca/~dave/BMW/e30/e30_85.pdf

I know it will end up being something stupid, just thought I would put that out there.

Cheers, Nathan

[JFry 1]

I'd check that the wires are connected to the plugs properly, might have come loose over time. Only thing I can think of.

[Forrest 35]

^ Yeah I am going to replace all the plugs. Might swap the relay too and see if it fixes it. Really can't see what else could go wrong really

[pureboiracer 0]

when the ign is on and your lights switched on and the bulb is in and everything plugged up put a multimeter from the neg terminal on the light socket to a part of the body, like a bolt that you know is earthed, if you have it on volts setting you should get a reading of les than 0.5v. that will make sure it is earthing ok. put multimeter between pos terminal and the same bolt u just tested from and hopefully that will read battery voltage +- 0.5v.

If your earth is ok then follow the wires back to the nearest plug, or where they join to the other lights to get power or whatever, check at any point you can along the pos wire for power, go from on the wire to ground and check for battery voltage with multimeter, keep following it back until you find battery voltage, at the point that u find voltage is the area of you problem.

[Forrest 35]

^ Cheers Oli, I will sort out a multimeter to borrow

[pureboiracer 0]

if you havent fixed it by weekend when im back from taupo let me know.

[Forrest 35]

^ Yup sweet I am in no rush. Am free Monday + Wed night

[pureboiracer 0]

^ Yup sweet I am in no rush. Am free Monday + Wed night

i dont get back from taupo until friday so cant do until next weekend.

[Forrest 35]

^ Okay sweet see how we go