[Real-GT]

I've been having some unusual problems with a 1989 MC19; whenever I turn on the left side indicator, the rear lights and instrument lights shut off (and turn back on as soon as the switch is reset).
When I first bought the bike this only happened with the instruments, however a few months back when I dismantled the front end to fix a few things it started happening with the rear lights too. Thankfully this doesn't effect the break light circuit, so as long as you've got your foot on the brake you can be seen making left turns.

This would suggest a short circuit somewhere, but I'll be damned if I can find anywhere obvious. The only clue is the bike used to be running 55/60w H4 globes with standard wiring—which may have already shorted something. I swapped these out for LEDs as soon as I realized they were H4s, then upgraded to an Ecliptech light driver (problem not affected by either of these modifications).

Does anyone have any suggestions on how to localise this? My loom is pretty shite looking at the moment, but I was hoping to clean it up when I repair this issue (see pictures).

 

[Real-GT]

Problem solved! It turns out the power to the instruments/tail (brown/white wire) was routed through a switch on the indicators that would shut off power when the switch was moved over to the 'other' side (in this case, left).

If something like this ever happens to you, take apart your LHS switchgear and check all the wires. Mine were dodgey as sin, likely a remnant of sh*te work done when the bike was complianced, and not obvious until you really pull back the plastic cover and see where the switch has been adapted for ADR.

In this case, the problem was fixed by splicing the brown/white wire with amber/white wire (coming out of the indicator switch). There's a good picture of it in hotwyr's post in the Switchgear - Oz Import vs Grey Import... post under maintenance.

Lessons to be learned: don't crimp/twist lock (solder and shrink wrap), and don't trust that some thing's done right if it's not stock.