I recently had the original windshield replaced in my 2002 325 sedan after I had a mishap with a wiper arm. The after market windshield was installed and I found a leak from the lower windshield through the dash and onto the carpet on the drivers side. The tail lights and headlights were going on by themselves with the car off (short in the electrical?). The windshield co replaced the window again and the same thing happened. I took it to a BMW dealer to dry it out and the dealer said that a piece of molding on the bottom that goes under the windshield was missing /not installed; the windshield co can not find any mention of this molding in their instructions. The windshield co is coming out again to replace the windshield for a third time; any thoughts as to the molding or could it be that they damaged the cowl? Thanks
Here's the parts diagram from realoem.com. Are you missing anything? It is common that aftermarket windshields don't fit properly, especially in the corners. Sounds like your Lighting Control Module is getting wet. http://www.realoem.com/bmw/partgrp.do?model=ET37&mospid=47720&hg=51&fg=05
I believe your light problem is not the headlight module its most likely is the turn signal/high beam stem on the steering shaft. I had the same problem with my lights, I would go out to the garage and my lights would be on, I replaced the light module but it didnt change anything finally took it to the dealer and $500 and a new stem later my lights worked correctly again. Oh ya I also had to put in a new windshield and have a leak when the car is in heavy rain.
Same problem! When my car gets good and soaked the lights have a mind of there own! At first I thought it was the moon roof drains but those tested perfect. Its my cruddy aftermarket windshield that is leaking and causing havoc! They also didn't replace it with the rain sensor so I have no delay wipers now... ARGH!