Z3 Dash lights conundrum

Greetings,

I bought a gorgeous black Z3 a few months ago - just turned 200,000 miles and looks and runs like the day it was new, really! Last week, I turned on the headlights and the cluster lights didn't come on. Everything else works. I checked the fuses (5 of them!) three times, but they all look good.
I have since noticed two other things. When the cluster lights were working, the odometer and trip lights would dim automatically when the headlights were switched on. These lights are still bright and do not dim when the headlights are switched on. Also, before, if I were to open the door with the headlights still on, there would be a warning sound to remind me to switch them off. This sound no longer comes on.

Is it my switch, or do I have a more serious issue?

Cheers

Cap'n Jon

how did you check the fuses ?

Visually. I should replace the fuses. I'm going to do that right now...

Fuses replaced. Did not fix the issues - however, the headlights on ringer is working. Still no cluster lights...any suggestions appreciated.

use a DVOM or test light to check fuses . get a repair manual and look up which is the dash fuse. is ANYTHING else electrical not working ?

Right...not sure what you mean by "dash fuse". The lid of the fuse box has all the fuses labeled. Everything works perfectly except the instrument cluster lighting. And thank you for taking the time...

The headlight switch is the issue. There is a rheostat the pops. Fairly common problem.

The //M roadsters have a problem with the lighted shift knobs shorting out the dimmer rheostat on the headlight switch.

Not saying this is the issue, but you might want to search got that, and check that out.

To me, the rheostat is the "dash fuse". There isn't any other protection to the dash lights.

Thanks Fred and Giznaz. I thought that might be the problem, after I confirmed that the fuses are all good. I suppose I need to replace the whole pull-out light switch?

You might not need to replce the switch. Randy Forbes posted a proceedure on how to bypass the rheostat. This make the lights stay on the brightest setting but saves buying a new switch. Now I wish I could find randy's post for you.

Thanks, Fred. It appears a new switch is around $40, which is not bad. I'm assuming that the rheostat is in the switch assembly? So, if I replace the switch, hopefully problem resolved...

I have not replaced the headlight switch yet. However, something bizarre happened yesterday - the fuel gauge all of a sudden went to zero (I had 1/2 tank of fuel). When I re-started the engine, it went to 3/4 and didn't move. I filled up the tank, it showed full, then 10 minutes later, went to empty and has stayed there. Also the read out showing miles left in the tank is not making sense! Could I have a computer problem? Everything else (besides instrument cluster lights and fuel gauge work perfectly)...

Another thing to check -

The wiring from the car to the trunk lid is in a black sheath. Cut open the sheath and check if the wires are broken. Opening and closing the trunk for 200,000 miles can bend these wires to the breaking point and cause a whole lot of weird electrical behavior in the Z3.

See TSB 61-02-99

Link to DIY Trunk Wiring Fix


I'd also remove the shifter surround and check for a broken wire on the lighted shifter.

.

Sounds like I've got my Sunday afternoon planned! Thanks for the suggestions...