Kill switch problem

[Nuzku]

Hello I'm new in the forum and with the k bikes.
I'm  from Finland and i have my first ever bmw bike (bmw k75s -86)
Its been built into cafe racer by the previous owner.
I have now had this broblem with the bike for 4 weeks, bike wont start with the starter (bumb starts will work), i have taken the starter of tested it it works, same with the relay it works, but i still got a new one just in case.
I have diagnosed the broblem being with the kill switch (not 100% sure if thats the broblem) but before when the bike did start when ever the kill switch was on speedometer didn't get any power and the brake lights was backwards (always on and when pushing brake lever turns of) and now its the same.
I have taken the kill switch apart, cleaned everything and checked the wires everything ok, and as previously said checked sthe starter and relay both should be ok. I have visually checked all the wires and have not seen anything unusual there. Have anybody else got the same broblem. I think here is more knowledgeable people than I'm with these kinda things, so any help would be appreciated so i can get the bike running still this summer.

[Laitch]

With the ignition switch turned to Off, put the bike in gear, pull in the clutch lever, then roll it backwards and release the clutch lever. Do that two or three times then turn the ignition switch to On and try to start it using the starter button. Let us know the results.

[Nuzku]

Hello, i did the thing you suggested but nothing.
Still no power to speedometer or to the start.

[Laitch]

The reasoning behind that suggestion was that a dirty starter is capable of causing lighting to work strangely. Back-spinning the starter using the method suggested sometimes can help shed enough of the built-up carbon interfering proper grounding of the electrical system to allow starting.

Custom motorcycles can come with electrical problems from the conversion to a custom speedometer and tachometer. What type of speedometer/tachometer is being used?

[Nuzku]

Okay thanks for clearing the suggestion.
I have already taken the starter off before to test if it works, it did spin both ways when reversing polarity.
My speedometer is Deytona nano II spo.
When i was tinkering and cleaning kills switch i got the speedometer to start up when connecting two right side wires in kill switch, but still nothing else happend when i try to connect rest of the wires.

[Laitch]

You should identify BMW wires by their colors in addition to their locations.