Diode problem?

[Christen]

I have a current problem on my 1975 XS650B between the starter button (starter circuit) and the brake lining warning light. When I turn the ignition key on and bush the starter button, the solenoid contact activates and the brake lining warning light comes on, no starter. I have double checked all the wiring and connections and wire insulation (outside the harness) in the handlebar controls, head lamp bucket, solenoid and starter. All good there. The only common component to both the brake lining light and the starting circuit seems to be the rectifier (diodes). I'm thinking that if the rectifier is faulty, activating the starting circuit could also activate the brake lining lamp circuit. I'm not strong on electrical systems but understand that diodes control the directional flow of current in one direction.
Does this sound plausible and if so, I see on other threads that many prefer replacing the OEM rectifier with standard (new) automotive rectifiers (Chrysler/Jeep, etc.). Thanks for any advice on this problem.
Christen

 

[Christen]

Answering my own question after further investigation and checking the starter and indicator light circuits: The diode is not faulty.
1. The brake warning light is supposed to light when the starter button is pushed.
2. The starter was faulty. A $14 used replacement is working well.
3. I used supper glue to firm up a wobbly connection between the two sections of the right rear signal light. This solved the loose joint but effectively insulated the two sections from each other, breaking the continuity of the ground connection. Dropping some solder into this joint soled the ground continuity problem.