1997 R1100RS replace bulb, low beam only still out

Happy Friday Illuminati

I researched a little bit before replacing my headlight bulb, thought it would be difficult to get into dash and wanted tips. My low beam is out, been out for months, don't ride at night enough to worry. Decided to replace it with free time. Got new H4 bulb, replaced with just a little wrestling with rubber cover on rear.
Lo-beams still don't work.

High beams work, high beam flash works. And, "Yes" this is with engine running, not just keyed on I guess I'm onto the switch, if you guys don't have any other brilliant suggestions, but...
Went back to fuse box and relays- why is there no fuse for headlight? Got the fuse box legend, got a nice diagram of relays from forum, checked out wiring diagram. Some discrepancies from year and model in what fuse 5 and 6 are? but nevermind, all are in clean and working order. Have owned about 12 motos? All old. Did I just not notice there is no fuse for headlamps? In my memory, don't think I've done one? Always assumed all circuits are fused? Is this a thing?

No Low

I have a 1994 R1100RS had the light mess and the problem was in the socket wired in new ceramic socket and problem was fixed.

The same supply feeds both Lo and Hi beam on the 1100RS.
It is unfused and comes directly from the battery via the load relief relay as a green/blue wire that feeds the hi beam switch.
The White leaving is Hi beam and the Yellow is Lo beam
As suggested, check the connector
Inspect the switch
Look for melted/darkened insulation close to the plugs & connectors
Double check that the replacement lamp actually works (I've had non functioning new - rare but it happens)

As suggested, check at the socket first along with the bulb. My guess is the problem is at the high- low switch. It should release from the bar with just one screw-I think. Try spraying into the contact area with electrical contact cleaner. If that doesn’t fix it try pressing against the switch with a screwdriver, pushing the moving part towards the electrical contacts. Just slightly! One of the hi-lo contacts wasn’t working on my RT a few years ago. Did that push as described and it’s been working fine since. Should be much clearer once you remove the switch and you can see the back side.

greenmachine1100 said:

m_stock, I think I know what you mean. A contact may have bent away during the years and 90k miles? bend it back a mm and it will be back to touching? I'll look and spray the whole assembly.
Will follow up on Sunday.[/SIZE]

Click to expand...

Think of it more like worn away as opposed to bent. Just to be clear, a mm is probably too much shift. More like one or two hairs.

greenmachine1100 said:

Excellent! Have not buttoned up. Will test socket base with voltmeter? Has ground, and I assume one is hi, one is lo. Handled and looked at socket closely, but can always REALLY look

m_stock, I think I know what you mean. A contact may have bent away during the years and 90k miles? bend it back a mm and it will be back to touching? I'll look and spray the whole assembly.
Will follow up on Sunday.

Click to expand...

Yes and references Brown which is ground.

Only Lo-Beam not working, solved

Just a help to anyone else searching solutions:
Left switch assembly does come off very easily with one screw. Other controls stay in place. Opened it and very, very dirty. Visible gap between yellow headlight rocker and housing- a little rubber boot or grommet would be nice in that spot. Lots of crumbly oily cake dirt. Maybe former owner had been spraying WD-40 into housing when this developed? Sprayed cleaner, sprayed canned air (computer cleaner/compressed air), worked switch, repeat. Was getting ready to disassemble further and clean further, took out some baby screws- but.... Was looking closely and saw a tiny, tiny f'n spring behind a floating tiny, tiny contact plate..... In the absence of a work bench (working in parking lot) and serious lighting, was afraid I would make matters worse. Tested it, got lo-beam to work, so called it a day.

I know without dis-assembly and some nice pictures this is hard to communicate- but I did use a pick to push that floating metal contact forward and backward. Back didn't do anything I could detect, forward (getting behind it) seemed to help contact low beam. Pushed it/wedged it with some force.Not really sure if that helped, because pick was metal and I was contacting the poles more or less. Got everybody to light up!

Last thing, the wired base plug of bulb. I can't tell if it is original BMW design, or a kluge. The rubber boot should cover that base, in a good design. Mine actually mates between the base and the bulb, leaving the connector base on the outside and the metal base of the bulb on the inside of rubber boot. If I go in there, again, I'm snipping the lead wires, leading them through the rubber boot, and then soddering them to the base. Then the base will be inside the protective boot. Can't think of any downside, except then the rubber boot is kinda stuck in position and you can't remove it easily. My model has pretty good room in there, and I think the boot has room to be massaged and finessed into several spots (it is very flexible rubber) if you wanted to get at bulb/base.

Thanks for your attention, Mates! Very nice to have some tips and what to pay attention to from the Cognoscenti. Helps with the confidence to get after it

Saturday and Sunny in Tucson! Hope you guys are riding, soon.