I have 4 used hazard switches, I do not know from what models they were removed. I bought them used.
3 switches have 3 wires, 1 switch has only 2.
All 4 have transparent red lenses with the hazard label in white.
I took 1 three wire switch apart and here is what I found;
There is a bulb. One of the 2 micro wires on the bulb was broken off. The bulb is wired between Blue/White & Yellow/Violet. (This does not seem to agree with another member's post above????)
I Installed a new 12V "Grain of Wheat" bulb from my model train supplies. It is not an exact fit, being slightly longer & skinnier and somewhat lower wattage.
The switch appears to be a SPDT switch with a factory installed stop block to limit it's travel in one direction creating in effect a SPST unit. (I'm not 100% sure of that fact).
Once repaired and tested, the switch was installed on my 1985 K100rs (was not equipped with one originally).
Testing the switch on the bike with KOEO, the hazards flash normally, but there is still no light in any position.
I have not started the engine to see if perhaps the flasher unit may light the switch only when the engine is running. I have no tank installed at this time.
Following are the resistance readings for all wires in both switch positions:
Switch off: YEL/VIOL to BLU/WHT = 55 Ohms, BLU/WHT to BWN = Open, YEL/VIOL to BWN = Open
Switch on: YEL/VIOL to BLU/WHT = 55 Ohms, BLU/WHT to BWN = 55 Ohms, YEL/VIOL to BWN = 1.3 Ohms.
Switch wiring on the diagram is as follows: BWN = Earth, BLU/WHT = Flasher Unit Terminal "C", YEL/BWR = Flasher Unit Terminal W.
If I have this correct, Closing the Flasher switch connects Flasher Unit Terminal W to Ground and Flasher unit Terminal 1 to ground through the bulb.
Since I have no knowledge of how the flasher unit works internally that is the limit of my understanding.
It seems that on my machine the flasher works equally well with or without the bulb wired into the switch.
I would guess that the flasher unit may be designed to activate the bulb through the BLU/WHT wire connection but it does not (at least with the engine off).
I would like to ask OTTO59 (above) what year & model he has that the switch lights on and if the switch light works both with KOEO and KOER (running)?
I would ask Inge to study the diagram he posted in a similar thread to see what should occur at the switch bulb & when.
Hope you all like the photos.
Regards, ibj...