xj1100 led headlight acting funny

I have a 1982 xj1100j with the headlight reserve lighting unit. I installed a led headlight bulb. When the key is on but not running it works good. No flickering and a clear low and high beam. When I start the bike it will light up but is dim at idle up to 2k and flickers. When I rev it up it gets brighter but it will engage the high beam automatically at about 70% brightness. So when I switch to high it only gets brighter not higher because its already lit up just not full power. It has a internal ballast or regulator. How can I override the RLU to see if it clears the problem? I have other led lights as a backup on a another circuit if the headlight fails. I need to have a brighter light and use less power as I now use a trailer with the bike and am old and need the extra light to see good at night. I ride a lot on back roads in the rolling hills and forest.

 

switch trailer lights to led lights if current lights on it use that much power.
have you checked out your charging system and battery? clean tight battery connections? how old is battery?

change back lights of speedo and tach to led.
if you change tail lights to led it will save you power but trip the computer into tail light warning,
go back to stock headlight bulbs and add off road led setups use 18 watts and would give you plenty of "head light"

 

You should be able to just unplug the RLU. They are usually (I say usually as I don't have a diagram for that specific bike) wired in parallel to the lighting circuit. They monitor the low beam circuit and apply current to the high beam side after the switch automatically when it "detects" that the low side is out. It might be causing your issues.

 

It would also be a good idea to check the alternator brush length, and the cleanliness of the traces on the rotor.

 

This has been on my mind as I have not replaced or checked them in about 12k ..... thanks for the reminder.

 

I will give it a try

 

I just installed 20w driving lights on my crash bars and wanted the power savings of the LED headlight bulb to compensate for the new driving lights.
The trailer has led's but I have not hooked it up since adding the led driving lights. So it's messing up without the trailer. I don't want to take the gauges apart at this time. The battery and connections are good.

 

I believe that is a mostly true statement, with the exception that power to the dimmer switch is an output of the RLU, so you must jumper the input to output on the engine harness side of the RLU to enable the headlights with the RLU removed. That said, the real kicker is the poor diagram (at least the one I have) that has obvious errors on wire colors and routing that is totally confusing. On the XS-11 forum they say to jumper the L/B (input) to L/Y (output), however my interpretation of the XJ is to jumper L/B (input RLU / output of starter switch) to L/W (output to dimmer switch). That may need to be verified first by checking the continuity of the L/W wire and make sure it goes to the common on the dimmer switch.

There will also need to be more work done for functionality:

The high beam indicator is wired into the RLU and would need to be re-wired to remain functional
The CMS is likely to set the "HEAD" fail when changing to an LED bulb, as a filament check is usually part of the protocol for the CMS, and the LED bulb will not provide the necessary low resistance to ground as a standard headlight bulb.

 

You are correct, I was able to find a hi res diagram for that bike and there would be some jumpering to be done. I am also noticing a mismatch of wire colors within the diagram so I will stop just short of providing some instructions here. @jamings67 , if you're interested in the diagram just shoot me a PM.