strange electrical problem

[BorS]

I had my bike totally apart, fitted a new clutch, oil pump, camshaft, 40mm Dellortos and and electronic ignition.
The bike started fine, some minor adjustment to the dellortos and ignition en than this weekeind it was time for a small test drive.
when I got to the first corner to the right and put out my turning signal a strange loud noise appeared. Stopped immediately because id did not sound good. It only happens when the turning signal to the right is on. Went home and looked into it.

When I use the turning signal to the left nothing strange happens, just the light go on and off, like the should. To the right, the starter motor starts to run , and that causes the noise.
When I pull the turning relais, there is no problem, it seem there is a connection between the turning signal and the starter motor?
Does anyone have an idea what could be wrong? please help, electrics is not my strongpoint.

Got the right schedule i think, it is a "79 R100RS
https://www.dropbox.com/s/aki0ay6j6d2tq ... 9.pdf?dl=0

[SteveD]

double posted...

[SteveD]

I'm trying to picture the scenario.

Forgive my lack of knowledge re: the 79. Does the right indicator button reside adjacent to the starter button? Is something in there crossed?

I have seen someone experience this when turning the bars to the right, if the starter button hits the tank bag.
Could this be it?

Unlikely if you're rolling at some speed and lean or countersteer a tad to corner.

[Airbear]

Did you remove the wiring loom when you had the bike apart? The only thing I can think of is that a wire is in the wrong place in the terminal board in the headlight. I would check that the Blue/Black wire from the left handlebar switch is in the right place on the Blue/Black patch on the board and that the two other wires connecting to that position on the board are also Blue/Black.

Here is a pic of my 1974 model terminal board:



Yours may look different, but see that in mine the Blue/Black area is right next to the Blue/Yellow which is associated with the starter cut-off switching.

Good luck. I'll bet you are keen to feel how your engine mods work.

[Airbear]

...
Forgive my lack of knowledge re: the 79. Does the right indicator button reside adjacent to the starter button? Is something in there crossed?
...

Steve, the 79 has the turn signal switch on the left handlebar perch. The starter cut-off circuit seems to rely on having sufficient brake fluid in the under-tank reservoir as well as the usual requirement to be in neutral and/or have the clutch disengaged to start. Nanny state stuff but I suppose the stats indicated that it is necessary.

[BorS]

Did you remove the wiring loom when you had the bike apart? The only thing I can think of is that a wire is in the wrong place in the terminal board in the headlight. I would check that the Blue/Black wire from the left handlebar switch is in the right place on the Blue/Black patch on the board and that the two other wires connecting to that position on the board are also Blue/Black.

Here is a pic of my 1974 model terminal board:

Yours may look different, but see that in mine the Blue/Black area is right next to the Blue/Yellow which is associated with the starter cut-off switching.

Good luck. I'll bet you are keen to feel how your engine mods work.

The Loom was left in the bike, but there where some wires lose on the terminal board, I would check this, there is a good chance that the problem lies there.
Thank you for you reply

[jimmyg]

Steve D's reply needs to be investigated before ripping into the wiring.

Tankbag isntalled?
Turning bars to the right, starter switch contacts tank bag?

It happens quite often, and ALWAYS happened to my wife riding her R75/5 Toaster with the soft tank bag attached.

jimmyg

[Airbear]

Steve D's reply needs to be investigated before ripping into the wiring.

Tankbag isntalled?
Turning bars to the right, starter switch contacts tank bag?

It happens quite often, and ALWAYS happened to my wife riding her R75/5 Toaster with the soft tank bag attached.

jimmyg

Yes, you are quite correct. That used to happen to me when maneuvering before setting off. My fix was to convert the starter button to a horn button and add a new starter button on the other side of the handlebar. Since I have a very loud air horn it is in my interest to never let the tank bag get in the way.

[BorS]

Found the problem, there was a fould with the wiring on the switch board. Like Airbear already suggested.
Thank you all for your contributions,

[Airbear]

Thanks for reporting back. Well done finding the problem.

So how did the test ride go, with the new Dellortos, etc?