1979 cb750kz neutral light

[Ronb]

I bought this bike and it had been in storage for about 9 years, i have eventually got it near finished and looking quite good but the only problem I have is when you pull in the clutch lever the neutral light comes on so you dont know if your in neutral or not. Is this normal for this model?

 

[amc49]

No.

There is a diode thinking somewhere around the battery, a black thing that joins neutral and clutch circuits together but power flows only one way, to allow both clutch switch and neutral switch to stop starter from powering up, but the diode is needed to prevent neutral power from flowing backwards into clutch to ground. That diode is likely bad or possibly turned backwards, it needs to plug in only one way, there is an arrow on the top I think.

 

[amc49]

https://www.partzilla.com/catalog/h...-a-limited-edition/wire-harness-ignition-coil

Part #10, or rectifier...........

 

[Ronb]

Thankyou will have a look

 

[Ronb]

Yes you were bang on found diode tucked under frame just in front of battery, tested and power flowing both ways. New part ordered, thanks for your advice saved me a lot of searching keep up the great work your doing, thanks again and stay safe.

 

[Ronb]

Just checked price on your parts post $27-61 £7.45 free postage UK Ebay, that very expensive in the us

 

[amc49]

It's just a cheap crap one way diode. if you have any electronics supply places then go there and find one with a higher wattage and 12 volt rating, you'll have to figure out how to make plug in spade for it but easy, cost maybe $2 US dollar. Or car junkyard, I know for sure that Ford Focus cars use them in the underhood fusebox, look for the black colored part with arrow on it. It would work fine.

 

[Ronb]

Diode now fitted and everything working as it should, thanks again