Never a dull moment....electrical guru needed

[yuddy]

Well guys,
Never a dull moment, now without warning, ........
NO HEADLIGHT OR GAUGE CLUSTER LIGHTS.......the rest of the lights work, including the gauge cluster warning lights but not the speedo or tach.
Given the fact that I suck with electrical problems,.......HELP!!!!
I have a 1980G model factory full dress.
I took the fairing off and checked all the connections, they are all tight and clean.
This thing has two relays in the lighting circut, but I don't know how to test them, the best I could do is verify that there is power making it thru the fuse panel, all other lights work.
Any ideas??
Thanks,
Ed.

[Dragonrider]

There is a relay under the gas tank, designed to leave the headlight off till the engine is started. The way it knows the engine is running, it there is a wire coming from the alternator (white) to the relay to trigger it . . . there is a diaode in that line somewhere in the harness to make it DC . . . mine went out, no more headlight.

Never actually found the diaode, so bypassed they relay. Now the headlight is on when you start the bike, but no big deal there . . .

So, check that relay . . . you need a manual to figure out the wire colors, I cannot remember them at the moment, except that the trigger wire is white.

There are 4 wires to the relay:

trigger wire-- (white)
ground (probably black)
power in (? red or yellow)
load--to headlight (blue?)

So, with key on, but bike not running, there should be power to the "power in" wire. (measure to the ground to make sure it is good)

If no power on the "power in"wire then bad fuse, connection, or key switch (connections inside)

Started, now power should be on the white wire (trigger), the "power in" and the load wire.

If there is power on the white and none on the load, the relay is bad.

If there is no power on the white the alternator is not charging, or the diaode in the line is bad.

If all is as expected, you have a problem somewhere else . . . check the manual for testing the "reserve lighting unit"

If the relay is white trigger wire is bad, Bypass the relay, connect the power wire to the load wire.

Hope all this nonsense helps. Good luck