No headlight/taillight/turn signals - 12.6V at the fusebox

[joeyplumley]

'80 (or '81?) GS550 L, non-running.

The electrics used to work (minus the turn signal, L would flash, R would just stay on). Working on various pieces getting it ready for the road, and decided to take another look at the turn signals to see if I needed to replace the flasher unit.

Well, turned the key to "on" and the neutral and oil dash lights lit. This time though, no headlight, tailight, or turn signals. Can't check the starter since clutch cover is off. All fuses are good (ohmmeter), and have voltage when they're supposed to (voltmeter). Voltage ground was referenced to the frame, not the battery neg post.

I would think the lights would ground where they're mounted. Maybe I undid a main wire or something?

Stuff I have off right now:
Tank
Seat
airbox (not removed, but unfastened)
carbs

PS - the bike hasn't ran since I've owned it, so it's not an over voltage issue.

Any ideas out there?

[joeyplumley]

Dang.... no one? I need a wiring diagram.

[Boondocks]

I don't have a wiring diagram for a 1980 GS550L, but I have a color wiring diagram for a 1980 GS1100L. Hopefully, it should be almost the same wiring setup. If you want to try it, PM me with your email address and I will send you the diagram as an attachment.

[ron bayless]

'80 (or '81?) GS550 L, non-running.

The electrics used to work (minus the turn signal, L would flash, R would just stay on). Working on various pieces getting it ready for the road, and decided to take another look at the turn signals to see if I needed to replace the flasher unit.

Well, turned the key to "on" and the neutral and oil dash lights lit. This time though, no headlight, tailight, or turn signals. Can't check the starter since clutch cover is off. All fuses are good (ohmmeter), and have voltage when they're supposed to (voltmeter). Voltage ground was referenced to the frame, not the battery neg post.

I would think the lights would ground where they're mounted. Maybe I undid a main wire or something?

Stuff I have off right now:
Tank
Seat
airbox (not removed, but unfastened)
carbs

PS - the bike hasn't ran since I've owned it, so it's not an over voltage issue.

Any ideas out there?

MINE DID THE SAME THING ONE TIME, I REPLACED THE FUSE EVEN THOUGH IT SEEMED TO BE OK AND THE PROBLME STOPPED.THE HEADLIGHT WIRES ON MY GS 1000 ARE YELLOW BLACK AND WHITE.THEY ARE LARGER DIAMETER THAN OTHER WIRES,PERHAPS ONE OF THEM HAS COME LOOSE.

[Busafied]

If your getting an audible signal on your ohmeter {if it has it} across the fuses then they're working.
Getting V on both sides of the fuse, then they're working.
Take your fuses out and GENTLY twist them to make sure they are not comming apart-

Take your V/M and check for V at the headlight PLUG-
You should have Voltage on one or the other side
{ones facing like this --> | } depending on if it is on the low or HI setting.
The Horizontal one at their ends is the Ground.
Check V in the Socket {using the Frame as the Ground}, move the switch and check both Vertical Parallel Slots both times while testing.

You may have lost power somewhere in the harness under the tank area {also could have a bad ground}, there are some quick plugs for the left hand controls {for the headlights} running in that area.

GL,
Ron