If someone owns a BMW 5 Series E39 model, they may have this fault. A headlight fault tends to show up somewhere within the 1998 and 1999 model years. It appears to be an issue with the offside high beam headlight staying on permanently, whether you have the ignition on on or off and the headlight switch in the fully off position.
When this failure happened to me, I had the lights on for a moment and when I stopped and went to turn the lights off again, I found that the main light just wouldn’t go out. I went into the house where I had to go to do work, but when I got back to the car about 10 minutes later the battery was already dead. After calling the breakdown service, the man started the car again and after a lot of nonsense he just said “yeah well it’s a BM buddy, it could be anything but it’s probably just a relay or something that’s stuck” . As a quick measure, I took out the light bulb to take home and pondered the puzzle all night.
The next morning I decided it had to be a relay that was to blame, so I searched the car for light relays. I checked the manual to see the location. I removed the panels here and there, literally removed all the fuses and relays I could find, took them all out, and put them back. And guess what the light still wouldn’t go out. So I started looking for answers on the web. I visited most of the BMW forums that I could find and found a few owners who seemed to have the same problem. Some of the answers they got were pretty similar, some people said it had to be a relay, someone suggested removing the battery for 10 minutes, then plugging it back in and everything should restart again and everything should be fine. I tried the battery idea, but that didn’t work either. So for the next week I went back to the web and finally someone said they had tried those things and then they finally gave up and took their car to a BMW dealership. BMW said there are no relays to control the lights and the all lights are controlled by the “LCM”.
Now the “LCM” is the light control module that controls all the lights. If this LCM fails, you just have to replace it. Easy! Aside from the LCM it is just a part of the main BMW dealership, and the cost, over £ 200. At the time, £ 200 was not an option in my pocket, so I drove the next few months with the bulb still unplugged. Then the day of the MOT started looming and there was still no pocket money to buy the LCM. So I called my desperate cousin to ask if he had any ideas on how to get the car through technical inspection.
He said, “Why don’t you cut the positive wire from the offending light, then run a new wire from the other light that works with it so they both work on the same supply? What a good idea! So I did exactly what The car went through MOT and another 6 months, it’s still running to this day, which is good because the £ 200 isn’t there yet.