K3 starter not working on switch

[Johny Boy]

Hi all, I'm having an issue with the starter motor not turning on the button.

I currently have the ignition hot wired, as I'm fitting a Moto Gadget ignition switch
Lights, horn etc all work fine , I.e. I have switched 12v working and the charging circuit works

I have a signal coming from the starter button (resistance change), and the headlight dims when I press it.
The clutch switch is also giving out a signal but I have bypassed it at the moment for convenience, as I don't have a signal from the neutral switch yet.
I have replaced the starter solenoid switch with a new repro one.

If I jump the solenoid it will turn over and start up just fine. But not on the button.

Does anyone have any ideas what I should check next?

Thanks
John

[Bryanj]

I think the K3 put power to the solenoid as against earlier bikes grounding the solenoid, the plastic insert inside the switch degraids and falls apart and is not available seperately, only as a complete RH switch.
In the US where they have headlight on all thectime its worse as pressing the button turns the headlamp off before connecting the starter.
Firstly check out how your system works then check contiuity in wiring and connectors.
Also look at solenoid and try powering direct with a jumper wire BE CAREFULL some pattern solenoids have wrong colour wires and can be wired internally totally different

[Rayzerman]

On some of these vintage Hondas, in the case of the switch being a grounding circuit, on some switches there's a metal part that grounds on the handlebars, and you may have to "fix" it by making sure it does make good contact with the bars....  on others, there were wires inside the handlebars. 
I imagine you could turn the ignition switch on and test there is 12V already at the solenoid, in which case, the switch will be the ground circuit???
Regardless, I'd disassemble the switch and give it a good clean while you're in there.