I'm facing a starting problem. I can't get a spark so i search in forums and found this Ignition Problems Due to Theft
I tested my diode and it showed 12v but as i understand i need 9v to start bike. am i correct?
I fixed the pink wire but still nothing. Tested my diode as you sad and it showed 12v. Look in pic where i connect wire, it dose not mater black to ground or red, it shows the same 12v not 9v. Diode position i didnt change.
Zener diodes work similar to regular diodes. They conduct ALL power unimpeded in forward direction. And block it in other. Zener will not block ALL power in reverse direction like regular diode. Instead above its break-down voltage, it will conduct limited amount across. Sapping some of input power.
That's why you're measuring 12v instead of 9v. Diode is connected in forward direction instead of reverse.
Show photo of how you have pink wire attached and how you're measuring voltage.
Cause and effect if you know difference. Lack of 9v on pink wire is not the problem, it's just effect of problem. Real issue is your diode is installed incorrectly in forward-bias direction and it doesn't reduce voltage going to ECU. Here's correct orientation, can you see difference?