81 KZ750 H2 Aftermarket Speedo

I’m working on my 81 KZ750 LTD h2 and I’ve decided to take all of the instruments off and replace it with just a mini speedo. However, I can seem to get anything to work, even the headlight doesn’t work anymore. The bike starts fine, but nothing else. I don’t have any turn signals, tach, or any indicators plugged in, just the ignition and the right hand controls to start the bike. Is there a failsafe I’m missing?

The headlight & tail light should have their own 10A fuses & the headlight wiring is routed thru the missing LH handlebar control, plus there's also a reserve lighting device for the headlight. The wiring is also routed thru the RH handlebar control & of course the ignition switch.

As for the speedo wiring, I guess it only has a power wire & ground wire for illumination. so you should be able to tap into the wire harness connector for the speedo. should be easy. a youtube video might be handy, depending upon what speedo it is.

So the LH controls are fine, I’m looking around with a multimeter and everything is complete, it’s just not getting power. I think there’s a relay that I’m not tripping. I’ve already skipped the reserve unit, and I have no turn signals. Are there any other relays?

There are two relays under the left hand side cover for the indicators and hazard lights.
The headlight won't work unless the LH controls are actually connected. You need power to the red/yellow wire from the LH controls for the headlight (red/black for high beam).
The taillight is routed through the ignition (red/blue from the fuse box to the ignition, then red from the ignition to the taillight).
There is a wiring diagram for the H2 in the filebase: www.kzrider.com/filebase/download/79-kz7...750h2-wiring-diagram

Edit: if you've bypassed the reserve lighting device then the blue wire from the fuse box needs to go to the blue wire on the LH controls (or maybe the blue/yellow - you can tell as the wrong one will just switch high beam and low beam around).