Howdy,

I have a 1985 K100Rs with 20,000 miles. The previous owner laid it down hard enough to rash the fairings and grind a hole in the valve cover case. I replaced the valve cover and got it running great. It ran like a champ. Then I had a few intermittent dim lights and bike died a few times and wouldn't start. I switched ignition and kill switch on and off till it started. I put it on the trickle charger overnight and then everything completely died.

I turn ignition and I get power to 1 turn signal and the brake light (bright not dim). The turn signal doesn't blink it just stays on. No fuel pump clicking, no response from starter at all. No dash lights or gear indicator nothing but the clock.

Ohm meter on Battery test 12.3 volts. Hooked it up to load meter and it was ok and went to high end of weak under load but not bad.
all fuses o.k.
cleaned and Tested ignition switch and it shuts power off and turns it on to fuse panel.
Cleaned kill switch and it seems to work fine.
Checked all connectors and main ground and they look brand new. Bike was always stored inside and only has 20,000 miles.
Pulled starter and cleaned brushes and rotor. Rotor was black with carbon and I thought for sure it was going to fire back up but nothing. same as before.
I have read Crazy Frogs tutorial (awesome!) But I have no power to anything but the clock and the tail light and blinkers (constantly on), so my situation doesn't fit.

The battery is a wesco but I don't know how old. Could it be bad? Would it power the tailights but nothing else? The trickle charger was a battery tender.

Did I fry something?
Relays?
Clutch switch?

It seems like the kill switch is off. How do you test relays? How do you test clutch switch? Do these kill all power except clock and tailight?

Mystery....

Any help would be much appreciated.

Welcome Freeboy!

Have checked if you got good battery ground, both at battery and gearbox?

What voltage do you read at fuse #1, with ignition on?

Thanks Inge,

I did confirm the ground to battery.

I'll check what the measurement is.

Any other ideas?

If you read low voltage at fuse #1, next step would be to remove the tank.

Then measure voltage the green wire (out) at the harness side of the ignition switch connector with ignition on
....if low, check at other side of connector...if still low check at the red wire (in) the same way.

If all this is OK, move to the RHS switch assy connector, measure the kill switch the same way,
green wire (in), green/yellow wire (out).

I turned the ignition on
the kill switch on
The battery direct at terminals was 12.1 volts
Fuse #1 (instruments) read nothing no voltage
Fuse #2 (standlicht) reads 12.1volts
Rest of the fuses read nothing.

ill do the starter and kill switch next

freeheelboy wrote:ill do the starter and kill switch next

You don`t need to check starter circuit, since it feed by fuse #1.
Check ignition and kill switch circuit as described above.

Ignition:

I put the ohmeter black probe on the main ground on the frame and I touched the back of the ignition each wire by itslef.

I got a constant 12.1 volts at the red wire.
When key was on I got a 12.1 volt measure on the grey wire (Registerd zero with key off)
The green and blue/grey wires registered nothing.

kill switch:

I got no reading from any wire on the kill switch.

freeheelboy wrote:The green and blue/grey wires registered nothing.

Then it`s the ignition switch that is the problem.
Here is is a how to dismantle and clean.

Thank you Inge,

I did it once but must have made a mistake. It was the first thing I did....

I will brush up on my high school german and give it another cleaning.

Kevin

freeheelboy wrote:Thank you Inge,

I will brush up on my high school german and give it another cleaning.

Kevin

It`s not needed, to read the pictures...........and you got google translate, then you get some fun at the same time.

Tusen takk!

Det fungerer perfekt nå. Jeg tror jeg samlet det galt sist gang jeg renset det.

Jeg virkelig setter pris på din hjelp.

Kevin

Gratulerer med resultatet.

Du gjør gode fremskritt med dine norsk leksjoner.

freeheelboy wrote:Ignition:

I put the ohmeter black probe on the main ground on the frame and I touched the back of the ignition each wire by itslef.

I got a constant 12.1 volts at the red wire.
When key was on I got a 12.1 volt measure on the grey wire (Registerd zero with key off)
The green and blue/grey wires registered nothing.

Inge, 
I'm having a very similar issue. Everything was working fine, then while installing a custom speedo for a friend I must have shorted the main ignition wire #6 (Green / black) thats in the instrument cluster wiring harness as I had a rogue spark (thought I'd taped the leads, but apparently not enough) which killed the headlight, brake tail light, and ignition. 

I tested and their is no power on FUSE 1.

I found this post and then popped the tank to preform the above test.

For me, I have a constant 12 volts at the red
no power at grey with the key on or off!

What is screwed up? Also do you have a link for a labeled pic for all the larger fuses under the tank?

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MikeisonTV wrote: What is screwed up?

Seems to be easier to start in the other end, which part of the electrics does function as normal?

I have no power on fuse 1, so no headlight, no brake light. The tail light works. When I turn the key now, NOTHING HAPPENS. The instrument cluster wiring harness has been snipped to accept the new wiring harness. Battery is new. I'm not sure if there is an ignition relay under the tank (in my pic). Or if I shorted the ignition module…?

Do you got power on the green wire at the ignition switch connector? (ignition on)

No sir...just on the red.

Then the ignition switch is the reason to the problem, check the link which is earlier posted in this thread...about how to dismantle and clean the ignition switch.

Ok, I decided to do some tests with my flawlessly running k100 and to test the "ignition switch" conection on it too to double check consistencies on my end with a solidly running ignition system. 

When you say  "test the green wire of the ignition switch." I'm taking by  "ignition switch" you are referring to the switch where the key is inserted? When I trace the line from this switch to its connector under the tank, and test the individual lines...I only get power to RED, no green even with the key to the "on" position. But this is the same reading from green on BOTH bikes!!!!! So are you talking about another switch? 

I Wasted no time for tests, I removed the Boesch ignition module box from  the troubled k75 and hooked it up to the  marvelous k100 and it works. One down.

I then test the 12v blue Boesch fuse relay  from the k75, it works fine too

MikeisonTV wrote: When you say  "test the green wire of the ignition switch." I'm taking by  "ignition switch" you are referring to the switch where the key is inserted?

 
Correct.

MikeisonTV wrote:When I trace the line from this switch to its connector under the tank, and test the individual lines...I only get power to RED, no green even with the key to the "on" position.

You should have power on the green wire only when the ignition is on.
The red wire is input to the ignition switch, the green is output.
Without power on the green wire nothing would function when ignition is switched on.
You have the ignition switch connected to the harness while doing the measuring?

MikeisonTV wrote:I Wasted no time for tests, I removed the Boesch ignition module box from  the troubled k75 and hooked it up to the  marvelous k100 and it works. One down.

Be careful with tests like that, as the ECU's is different......

MikeisonTV wrote:I then test the 12v blue Boesch fuse relay  from the k75, it works fine too

The blue relay is for the ABS....which seems to be out of use, as the warning lamp relay is removed.

You should have power on the green wire only when the ignition is on. wrote:The red wire is input to the ignition switch, the green is output.
Without power on the green wire nothing would function when ignition is switched on.
You have the ignition switch connected to the harness while doing the measuring?

I do NOT have the ignition switch attached when administering the test. I've been disconnecting it and testing the colors on its attachment plug on the wiring harness....but writing this I realize how foolish this is....if it's disconnected, how could it register that the key is at the on position. 
(How embarrassing)
  
 I'd love to be inadated with the correct location on the bike for testing the ignition switch. I'm assuming I should trace the harness further back to its point of origin?


(Good to know on swapping the Boesch ignitions from a K75 and k100...I thought they were the same. Thank you for the education. I sincerely appreciate you always being so forthcoming with your knowledge and time)

The easiest place to measure the green wire downstream from the ignition switch
is at the connector for the RHS switch assy
(Connector With 8 contacts under the tank on the RHS).

This wire is the input to the kill switch...output is green/yellow.

Well, when I began to start your test...I turned on the ignition to test the green wire, and the headlight came on! "What's this?" I gleefully chucked in my head. Then, "how about bout I just push the start button"......and boom....she is excorsized!! 

Thank u Father Inge

Congrats, I would guess that the problem gonna repeat itself in a short future.

Then check the green wire, if no power....the problem is in the ignition switch
or related connector/wires.