Yamaha YTM200EK Tail Light and Headlight not working

[eBoyDog]

I'm trying to get the lights working on my trike, the headlight on/off dimmer switch on the left handle bar works when then key switch is in the LIGHT position with the engine not not running but from the wiring diagram I see the the tail light should come on when the the engine is running and the headlight should work when the handlebar switch is on the on position. At first I thought that the lights only worked when the key switch was in the LIGHT position but now that I have gone though the wiring diagram I understand that the LIGHT position of the key switch is only for when the engine is not running.

I have checked the tail light bulb and it's good along with the wiring from it, I haven't checked all the wiring up to the keys witch.

Is there any known common issue with these trikes regarding the lighting? The only thing I could find was the voltage regulator which can blow out the bulbs if it's bad but that doesn't appear to be the issue.

I'm preparing to tear into the wiring and start checking the connectors to check that, also the wiring diagram shows diodes inline in several places, are these known to be problematic? If I do find a a bad diode, can I replace them with standard 12 volt diodes or is there particular type I should use? There doesn't appear to be any wiring butchering on this trike, all the wiring appears to be original with no hacking or repairs but I guess anything could be there.

Thanks for any advice you may offer! I'm wanting to take the trike to a off road riding place but they require working lights and I was turned away last weekend because they didn't work!

[eBoyDog]

I found the problem was simple, the switch on the left handle bar was bad. The switch contains two set of contacts, one for when the ignition switch powers the headlight and the other which switches the tail light and headlight when then engine is running.

After taking the switch apart and cleaning it, it now works right. Only major remaining problem is that my lighting coil appears bad as while the headlight and tail light works, the are very dim with little change at higher engine rpms so I have a new lighting coil on order (I'm going to replace the charging coil too since I will have to pull the stator apart).

I think I'm going to have a nice 3 wheeler now that I have sorted out the electrical and engine starting problems.... Now on to better things like fixing up the cosmetic issues!