Intermittent Problems with Gauge lights, Turn Signal indicators, and Radio

[e396speed]

So I bought a 1999 540i/6 a couple weeks ago with some electrical problems and I'm not quite sure where to start. Sometimes the gauges and most of the dash lighting is extremely dim, just barely visible at night, no matter what the dimmer is set at. They come on bright for a split second when turning on the headlights then go dim. Other times they work fine and the dimmer can control them. The turn signal and high beam indicators hardly ever work but the actual lights work outside. Also the radio has never worked right, it doesn't come on when you want it, but it comes on by itself sometimes, stuck on a station and the display turns on and off and goes though different modes while the audio keeps playing. I tried removing the radio, but that had no effect on the other problems.

Just wondering what you guys think is most likely the cause of these problems? Ignition switch, light control module, battery, GM3, short in wiring somewhere? I tried the visor test for the ignition switch and the light came on bright and had no effect on the car. Also my door locks seem to work with the remote and the interior door lock button so maybe its less likely to be GM3? Though I might remember the door lock button not working at first when I drove the car home, not sure.

Any suggestions would be greatly appreciated, thanks!

[JimLev]

Have you looked at the fuse box under the carpet on the pass side? It's just ahead of the right seats track.

[edjack]

Hope it doesn't look like this: http://photobucket.com/gallery/user/...NTU1Nw==/?ref=

http://www.bimmerfest.com/forums/sho...d.php?t=459397

Scroll down to "PROCEDURE TO REPLACE FUSE #107 UNDER PASSENGER SEAT" to access the fuse panel.

[e396speed]

Well I just got done checking that fuse box (edjack's link was very helpful!) and it doesn't appear to be the problem. It was in great condition and all the fuses had 11.98 volts going though them. It looked like someone had been in there before because the foam was already ripped.

[JimLev]

11.98 is pretty low, indicating your battery isn't in the greatest of condition.
How's your ground connections? Neg battery cable to body, engine to chassis connection?

[edjack]

Yeah, about 50% charged. The E39 is voltage-needy.

https://www.google.com/search?q=batt...tm%3B922%3B408

[jclausen]

I put an ignition switch in as preventive maintance, I wasn't going to wait for it to act up. I would try the ignition switch

[Chedley]

Yeah, about 50% charged. The E39 is voltage-needy.
….

I'd say the E39 is a voltage queen or bitch... The last head-fake problem I had on my car is the ABS trifecta -- fixed by an overnight recharging of the battery.!!

And no , I am no battery sales-man.

[JimLev]

Chedley, we like to joke around here, sometimes you need thick skin.

[e396speed]

Wow I didn't realize 11.98 was so low! I just checked the battery with the volt meter this evening. When I first checked it, it was 11.9 something and around 14 with the engine on. After taking it for a 15-20 minute drive it was 12.3 or so with the engine off and 14 with it on. Maybe it was just low from the car sitting for a while and me having the doors open a lot keeping all the interior lights on. I also did test number 2 on the gauges and all the indicator lights seemed to be lit up including the high beam and turn signal arrows, so maybe that rules out the gauge cluster. It might be worth mentioning that one of my low beam headlights burned out a while ago and I don't see a warning about it on the gauge cluster. Could that be an indication of a bad LCM?