110 hanmar5 5 pin cdi .With the engine running the rear tail lights work fine with low beams however when high beams are selected I loose the rear tail lights . The brake lights work fine in all cases. The bulbs are good. The head lights are fine in all cases, OFF, LOW and HIGH. I understand the engine must be running to get 12 volt power to the bulbs EXCEPTION TO THE RULE IS THE BRAKE LIGHTS. Does anyone have any ideas ?

 

Your light switch is bad. There are two separate switches in the light switch ganged together on the same slide bar. One section controls the tail lights, and the other controls the head lights. I think one of your slide connections for the tail lights isn't making connection in the high beam position.

The 'tail light' switch section is supposed to connect power (be it AC or DC depending on the quad) to the tail lights in both the low and high beam positions.

On the other hand, the 'head light' switch section connects power (be it AC or DC) only to the low beam filament in the head lights in the "low beam" position, and switches the power over to only the high beam filament in the head lights in the "high beam" position.