Progressive lighting failure... where to start?

[Gflem]

Hi, all. Frustrated owner of a 2000 Katana here.

When I bought it, there were several modifications made to the bike, one of which was a "both-headlights-on" mod, with the hi-low selector switch retasked to be an on-off switch.

The problems started with the headlights turning off when I'd hit a sharp jolt on a freeway. A panicked smack to the left side of the upper fairing used to turn them back on. Now that's not working.

The problem has progressed to the left turn signal in the front.

I have checked the fuses already - I noted that there was a bit of discoloration and darkening on the fuse contacts, and a bit of bubbling, but the fuse was solid. Replaced it anyway and the headlights still don't come on.

Where should I look next?

[uncltommy77]

Obviously a short somewhere or something loose. Check all the wiring for loose spots or darkening or burnt. Bout all I can do. Sorry dude!

[92xjunker]

I believe if your in the US, both head light are used at the same time. Thus you had electrical issues before you bought it. Pull the fairings and inspect the connections for corrosion and heat damage also check the bulbs and hand control, since your problems are on the same control.

[Paladin98]

I had problems with my 1998 750 lights working only intermittently. I found bad contact in the wiring harness plugs. You could feel them get hot to the touch, even after cleaning. I cut the bad wires on either side of the plugs and used marine grade butt splices with heat shrink and glue. I have had no further problems.

[hardlydangerous]

remove the right and center fairings

unplug and clean the yellow and black connectors for the headlight and controls. (on top of the headlight)
clean and lube with a bit of wd-40.
the female sides use a very fine flat blade screwdriver and slightly pinch down the female connectors in the plug for a tighter fit.

[Gflem]

Thanks all.

Will give the stated recommendations a shot and update once complete.