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K100RS Turn Signal Issue

joeangi

New member
I have a 1986 K100RS (bought new) and the turn signals have started acting up. When the bike is stopped they randomly work/ don't work, sometimes only one blink. This happens to both sides. I have cleaned the switches, and since in happens to both, I do not think it is in the handgrip switches. When the bike is rolling, they seem to work fine. Every once in a while, they won't work, but stopped, most of the time they will not work.

Relay? I would think that it would happen all the time. I was under the tank last week, and all is clean and tight. Grounds look good. Anyone have any ideas

Thanks for any ideas.
Joe

BTW battery is one year old, and is right off the tender so voltage is good.
 
Check for corrosion on the sockets, on the shell and on the inner central contact.
Also check the bulbs themselves; not just for corrosion, but the center contact is just solder - this can wear down or deform.

A long shot but it's happened: one or more bulbs may have a broken filament that is still touching at the break; this can sometimes be spotted only with a magnifying glass. They're cheap, replace 'em anyway. Try to avoid the Phillips brand; these are supplied as OEM in many vehicles, and they're cheap for a reason.

My K100 had absolutely ZERO "service loop" and very close to zero stress relief all along its wiring - you may have an intermittent break, the hardest thing to nail down.

Major clues when it happens:
1) do both sides fail
2) do the front and rear both fail on one side
This should narrow down where the gremlin is hiding.
 
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Thank you for the reply. I will get some new bulbs...sounds reasonable, as they are getting old. It happens on both sides, so a wiring break is not out of the question. When the bike is moving, it may generate enough vibration to keep the wires touching,when stopped they move slightly apart? It is hard to track down, as when I go to work on it, they work fine...

Joe
 
Are both front and rear lights failing or just rear?

If just rear and both are failing what is a common connection point? On my 85 K I believe there is one common connector under the fuel tank for the turn signals and possibly another under the seat or tail section. I can't remember on my 85 if the ground connection is common on these or not.

Good luck
 
Is the connection easy to unplug and re-connect? If so, try bending the curled ears on the female connector with a sharp pick. I have had to do this with the turn signals as well as the speed-o-meter pickup connection.

Mike B
K100RS
 
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