Battery Dynamo Draining Battery.

[Nimbus]

I would be extremely grateful if someone would be able to tell me how to rectify this fault. I have a 1940's 6 volt, negative earth, motorcycle with no lights, or fancy electronics, and the fully charged new battery will go completely flat after 30 minutes with the engine running. The red charging light stays on and someone has suggested that this indicates there is a current drain to the dynamo and that the dynamo is trying to run as a motor. Using a multimeter on the battery terminals indicates that the battery is being charged.(?) So far I have replaced the battery, regulator, bushes with no effect. The dynamo is of the Bosch type and the regulator is the correct one. I've tried isolating the warning light but the symptoms remain the same. Would connecting a suitable diode somewhere in the wiring be a practical solution ?

 

[Nimbus]

funny. i'm looking for a restoration project, barn find perhaps, a 1950's /60's British M/C 500 ish cc. AJS, BSA, RoyalEnfield. Arial,Triumph, any. any one know of anything going?

There's plenty of vintage/classic project bikes on eBay and Facebook marketplace. Good Luck !

 

[DPG]

funny. i'm looking for a restoration project, barn find perhaps, a 1950's /60's British M/C 500 ish cc. AJS, BSA, RoyalEnfield. Arial,Triumph, any. any one know of anything going?

Always plenty of Bantams for sale.

 

[telectrix]

Always plenty of Bantams for sale.

never fancied keeping chickens.

 

[telectrix]

There's plenty of vintage/classic project bikes on eBay and Facebook marketplace. Good Luck !

looke all round ebay. prices are stupid. most sales are for restored or partly restored bikes with price tags 4 figures.