passenger headlight

Hi all
I replaced my lkm and it lit up the whole car! I recommend to anyone who is having crazy light problems. My new question is what could cause my passenger side headlight not to work.
Every other light on the car works. Like I said I have a new lkm, all fuses and relays are good, brand new silverstar lowbeam headlight bulbs. Connections are clean and have electric grease on every single bulb.
The only thing that comes to my mind is that some how there is a short to ground.
If I had a bad ground at that light would it throw them all off?
I have a 1990 m20 e34.
Help?
Thanks!

Well I would first test the bulb for continuity.If good - test for 12v at the connector wile on. if no power, possible relay or fuse bad. If yes test the brown wire lead in the socket for continuity to a metal ground. If good possible switch issue. car fully examine the socket that the bulb seats in for heat damage to socket.

Thanks luckydog! I had my meter out for fifteen minutes it did not check the ground wire.
I checked resistence on the bulbs themselves, for 12v with test light and meter but did not check the ground and that was my original thought in the first place.
As soon as daylight hits I will check the ground.
I cant believe I didn't check that.
Once again thanks! I will post results when finished.

Turns out everything was ok, but the new LKM. I recommend that you get a brand new one or are very good with soder gun. I did the later and now they are perfect. I have to aim them a little more but finally the headache is over. Thanks for all the great advice!