'04 R1150RT - High and Low beam failure, any ideas?

Just noticed this tonight when I pulled into the garage tonight. The high beam indicator light was on no matter what position of the high beam switch. Looking, I discovered that both the high & low beam lights were out, but the parking light was on. I shut down the bike, waited, turned the bike on, same symptoms.

The fog lights work, so do all the other lights, just the high and low out with the high indicator on.

Looked through all Clymers, Haynes & the ops manuals and I cannot find any fusing for these lamps. The only controls seem to be the high beam switch and the Load Relief Relay. Since everything else works and the wiring diagram shows other devices off the relay, that doesnt seem to be the problem and the high beam switch doesnt control the low, so that doesnt seem to be in the path.

Any ideas or areas to check?
Thanks
Kevin

bulb(s)?

That bike has an H4 bulb, I think - and losing both beams does sometimes happen.

The headlight switch is a three position switch: low beam, high beam, and flash for that curious European custom of flashing headlights at slow drivers, cows, roadside attractions, etc.

You can test the high beam filament by using the flash switch. If neither the flash nor high beam switch settings cause the high beam to light, it is probably the bulb.

Or, it could be the connector at the bulb. They sometimes make a bad contact. In this case probably the ground contact.

The main ground seems to be OK since the parking bulb still works - and it uses the same ground wire from the housing to the frame.

I would start by pulling the connector and testing at the connector terminals for power. Yellow wire is low beam, white is high beam, brown is the ground. Look for any signs of heat distress, warping, melting, etc.

If you have +12v at white on high beam and yellow on low beam, then check the connector for the ground wire for continuity to ground.

Then probably replace the bulb.

The 04 RT has seperate bulbs for high and low beams. Low beam is always on and the high beam lamp comes on when switched on at which time both bulbs are lit. I don't think both bulbs would fail at the same time, but anything is possible. I believe I would check all the connections first. Make sure they are clean and tight. I don't know if there is a relay in the system or not, if so it may be the culprit. Also a bad ground would cause a failure. Electrical gremlins can make you say dirty words Good luck and let us know what you find in case my RT decides to act up.

It's not uncommon for the ground tang on the headlight assembly to break. Look there first.

My apologies, I forgot to add that I had tried a replacement with a known good bulb. I have +12v on the Low beam, but no Ground, so the tang sounds like the culprit.

Flashing the high beam switch doesnt help.

@norton: How hard is the ground tang to find?

Thanks to all!

Kevin

Fixed!!!

@norton: I owe you a drink or 5 if we ever meet. The tang below the light bulbs had some corrosion and just moving them around a little cleared up the problem.

Some one in BMW design had a little too much beer at lunch the day they designed that tang. Just by pressing it, the light got brighter, indicating a poor connection. I am trying to get some pics to show the problem area.

One day I will pull the front apart and figure out a better ground system for the bulbs.

Thanks for all the pointers!

Kevin

head light

masonke said:

Just noticed this tonight when I pulled into the garage tonight. The high beam indicator light was on no matter what position of the high beam switch. Looking, I discovered that both the high & low beam lights were out, but the parking light was on. I shut down the bike, waited, turned the bike on, same symptoms.

The fog lights work, so do all the other lights, just the high and low out with the high indicator on.

Looked through all Clymers, Haynes & the ops manuals and I cannot find any fusing for these lamps. The only controls seem to be the high beam switch and the Load Relief Relay. Since everything else works and the wiring diagram shows other devices off the relay, that doesnt seem to be the problem and the high beam switch doesnt control the low, so that doesnt seem to be in the path.

Any ideas or areas to check?
Thanks
Kevin

Click to expand...

Hi had this happen to my 05 rt $600.00 for new head light plus installation at BMW so I took matters into my own hands, the wires on top of the light assembly were burned through so I installed new wires onto the bulbs and changed the highbeam holder from a car forget which car but some reaserch will tell a lot

PGlaves said:

That bike has an H4 bulb, I think - and losing both beams does sometimes happen.

Click to expand...

I thought it takes two H7 bulbs.

Greg_K said:

I thought it takes two H7 bulbs.

Click to expand...

H7 is the low beam, H3 is the High

I have the same problem on my 04 1150rt. So what is a ground tang and how do I find it?

no lights

I had the same thing happen a couple of months ago on my 02 rt.I was getting power to the bulbs but no ground and my parking light and fog lights worked.So I looked at the wire diagram and the same ground went to all the lights but they split of the main ground to the fog lights,the parking lights,and the head lights.So I grounded the head lights to see if they would work and they did,So were the ground wire went into the back of the head light their was just enough wire to but a wire spliter on the ground, and just found a good place to ground it to the bike and no problem since.

Thank you, I mentioned the comments to the technician working on my RT and sure enough, the problem was with a burned out ground wire.