diagnosing headlight woes

[toomanybikes]

Disclaimer - Electricals are my weakness

The headlight on my naked '81 1100 is not working. After pulling off the Vetter fairing, I mounted a new aftermarket light from 4into1 which worked recently on this bike but stopped working during a ride this past week. After checking the common cause (fuse, loose wiring) I tested a known working headlight from a GS550, which also didn't light up. There does not appear to be any juice making it to the three prong light connector, so the problem is somewhere upstream of that.

The fuse is receiving juice and the tester lights up on both sides of the fuse. All other lighting works (signals, rear light, f/r brake light, horn, etc.). the only other electrical issue is the rear suspension pressure light is always on since I removed the shocks and haven't (yet) grounded the wire. I can't imagine that should impact the headlight .. famous last words.

The LH control seems fine (see pics) with no apparent loose wires or excessive corrosion. Does the switch rely on the positioning nub and hole in eth handlebar for grounding?

Any ideas or other things to check?

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PXL_20220514_153939402.jpg (99.23 KiB) Viewed 111 times

[Whiskerfish]

Open up your starter button control and spray it out good with some contact cleaner. The power for the headlight goes through that.

[toomanybikes]

Open up your starter button control and spray it out good with some contact cleaner. The power for the headlight goes through that.

Thanks, I was not aware of that. I need to make a beer run and the HW store is (not surprisingly) near the beer store.

[toomanybikes]

UPDATE - Yep, contact cleaner on the starter button fixed it, as shown by the ring of fire on the towel in the pic below. Awesome advice.

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[Whiskerfish]

[pidjones]

Another thing to care for NOW: Vetter supplied their fairings with the worst electrical connector ever produced - the Scotch-lok. Not only poor contact, but severs wire strands and ruins the insulation. Find each one of the wounds to your wiring made by them and check for cut strands. If they are cut, re-splice properly. This is particularly important on the high current headlight wiring. Heal cuts in the insulation with shrink tubing or liquid electrical tape.

[toomanybikes]

Another thing to care for NOW: Vetter supplied their fairings with the worst electrical connector ever produced - the Scotch-lok. Not only poor contact, but severs wire strands and ruins the insulation. Find each one of the wounds to your wiring made by them and check for cut strands. If they are cut, re-splice properly. This is particularly important on the high current headlight wiring. Heal cuts in the insulation with shrink tubing or liquid electrical tape.

Already done. I left one or two of the hard to reach Scotch-Loks in place and simply cut the wire instead.

I'll double check today since I have to fix a minor wiring issue with the instrument panel signal indicators.

[gltriker]

Ìs the GL1100 starter button headight contacts as vulnerable to overload as the GL1000 starter button headlight contacts are?

12volt relay installation a proactive consideration on this model, too?