Wait. The 75 K1 has the same basic electrical as the 74. LH control should have a headlight on off switch, as well as the LR turn switch. The F model had no headlight off on switch, and the starter button had a headlight interrupter while the starter was engaged to keep the ignition voltage high during e start. Yes, that switch often disintegrated. But, the 74-75-76 K model starter button switch is pretty robust.
If front TS aren't working, check the bulbs, they should have two filaments (1157s will make the stock flasher unit not work right, I don't recall the proper number off hand, but they are lower wattage 1056/1034 possibly). The rears have only one filament. Check to see if you have the correct parts installed. The fronts are run lights and turn lights (two elements). The run light turns off when the blinker is selected.
The fronts also need a proper ground to function correctly. The headlight mount bolts at the ear should have nuts inside with green connection grounds that wire directly to the harness inside the bucket. The forks ears are rubber isolated from the forks and frame, hence the need for this wire ground for the stalks of the signals.
