Headlight / Switch pod

Hello, So my 1979 kz750 twin headlight stopped coming on awhile back and after sorting out other issues I can finally work on this one. My headlight comes on when hooked up to my truck, But not when hooked up to the bike. Fuses are good, 3 prong plug to headlight was just replaced, and I have alittle bit of voltage in my switch pod.I set the meter to 20v and I get 0.652. From what I can see the switch box is faulty. All of the wires read the same voltage .Considering everything else works except the headlight, I want to say its the switch pod. Can anyone back this theory up? I will replace the switch if that is the issue. -Tyler
Btw- front turn signals were removed if that has anything to do with the circuit.

Wiring diagram for the 79 750 twin. Could be a switch or a harness connector or a fuse connection or just about any connection point.

Thanks alot for the diagram . The one I have was printed so its hard to read . Headlight is on. yes