Strange light bulb problem FIXED!!

[jbach36]

I posted previously about my exterior light bulb problems. I was getting a warning light on my dash that one of my light bulbs was "out".

When I checked the taillights and compared the left cluster of lights to the right cluster of lights, there was always a right rear bulb that was out that I kept trying to fix. I tried new bulbs, scraping off the 'calcium' build up that gets on the metal, etc.

As it turns out, it wasn't that the right bulb was OUT, it was that the LEFT bulb was ON!! It wasn't supposed to be "on". Plus I had a front left side marker bulb that burned out so I replaced that one with a spare that I had around the house.

After tracking the problem down to the headlamp switch and replacing that with a new one, I STILL had a problem! Some here thought it was a grounding wire and other issues.

Turns out the problem was that I used the WRONG LIGHT BULB in the front left marker! The kicker is that the replacement bulb was WORKING, but causing problems with the rear bulbs!! The CORRECT BULB has TWO connector points on the bottom. The one that I was using only had ONE.

So, expensive lesson learned, USE THE RIGHT BULBS!!

1991 300d, 215k