Lights are being extremely odd

[didgeridoodude]

Just to be blunt, here's a list of odd things that my lights are doing.
1. left indicator flashes quickly, goes to normal, back to quickly and whatnot on random occasions. I have replaced all of my bulbs, I know that's out of the question.
2. Left indicator signal on the instrument cluster (the green arrow) stays on but does not flash, and when on, the left indicator does not work.
3. Reverse lights haven't worked since I owned the car, nor the fog lights.
4. The rear left brake light doesn't shine as bright as the right rear when my foot is on the brake. Sometimes, the left reverse light may want to work.
5. The light that goes off when the door opens is no longer being sensed unless I manually toggle with the switch but the right door light hasn't worked since I've owned the car.
1991 318is.

[bmwman91]

1) Possibly the blinker relay. Grab one form a junk yard & swap it in. It lives under the plastic in the steering column.
2) Probably the relay.
3) It could be that the backup switch is unplugged. Jump under the car & check the passenger side of the transmission to see if both wires are attached. You may need to remove the heat shield, I can't remember.
4) Check the wiring harnesses back there for damage.
5) Weird, the door should hit the switch. Play with the little black switch on the passenger side dome light...maybe it is off?

[DesktopDave]

You need some good contact cleaner.

The passenger switch isn't making good contact, it needs pulled & replaced or maybe you'll get lucky and it'll be work after a good contact cleaning.

If the turn signal works to the right, you have a short somewhere in the harness.  I'll bet it's either that troublesome connector behind the front bumper, or the signal is cracked/foam seal failed and the turn signal has filled with  water.  That'll short the whole deal out so the turn signal relay won't blink.

I have occasional problems with loose barrel connectors in my rear left signal housing too.  I have to take it apart and crimp the barrels a bit tighter one of these days.  Occasionally the left signal goes into fast-blink mode, like a burned out light would.  Fiddling with the twist-lock in the trunk fixes it for a while.

3500 posts!  Can't believe I've been here that long...but these cars are just that much fun, I 'spose.