So almost done with worrying but stumped on last thing. The turn indicator bulb in the cluster. Where in the world does it bug into. I assume one is ground and the other is hot but you can hook it up to both left and right side lights, and if you pick only the left for instance. Yes it will light up when you use left signal but won't if you use right. So what am I doing wrong. It's weird unless I'm reading the wiring diagram wing it shows both the hot right and hot left plugged into the bulb.

I'm guessing the wires coming out of the bulb holder are dark green (can look black in poor light) and dark brown? They each plug into their respective three/four pin female multi connectors in the headlight bucket and Bob should be your uncle.

So both wires are hot but how does that work if they are the same bulbs how does it ground out then? I think it is the green and Brown one but then again I was syphoning parts from a donor bike and could be using a random bulb holder with other color wiring from 1 of the other lights for that one. I'll have to check

I'm no electrical expert, but likely will be tied in with sharing the three/four pin blocks and also the handlebar switch. Often I know what works, but not how, and so try not to think about it too much!

Going back 50 years i think yamaha always had dark brown left and dark green right. The flasher indicating bulb in the tacho will have both those colors, one to each double connector in the headlight. Cant quite justify that statement as thought it would backtrack through that bulb to bring both left and right on but maybe not. won't confuse you anymore, now i'm confused.
Thinking a bit more--the relay will have a light brown powering it, "light brown being the hot wire after the ignition switch", & other relay wire will go to the flasher left right switch on the handlebar. If there's a third wire on the relay it'll be earth black. Some relays we had were just two wire though. Not sure what bike you have but yamaha stay the same in respect of wiring colors.

The indicator bulb is genius in its simplicity.

One side is connected to the hot wire from the left and the other is connected to the hot wire from the right.

The gauge indicator bulb is like 3 watt. At the turn signals on each side you have like two 21 watt bulbs.

Only 3 watts can flow through the gauge bulb... that's not enough to light up the bulbs on the opposite side of the bike but the bulbs on the opposite side of the bike are enough to provide enough ground to allow the gauge bulb to light.

So when you signal left, gauge bulb gets power from left side signals and grounds through right side signals.

When you signal right, gauge bulb gets power from right side signal and grounds through left side signals.

Works great.

If you try to install LED's or some other low wattage signals you might end up with all four low wattage lights flashing but if you leave it stock you'll be fine.

That explains it thanks MarkT.

Dont forget to add the ground wire from the battery box bolt that holds the flasher relay to the loom, flasher wont work if it's not properly grounded.

That was it the two wires go to the power wires for each front light. I would never have thought that would work. Oh an I was using led bulbs in cluster also and like the one guy said as soon as I replaced it with a traditional bulb it lit up. Thanks all.