Blinker won't blink

My right directional on my 1980 KZ750-4 LTD won't blink on and off. I can manually blink it by turning the turn signal switch on and off, but it won't do it by just flipping the switch. The left one works fine, and I thought they both used the same solenoid or rectifier or whatever for the blink function. Anyone have an idea what's wrong?

Sounds like a bad turn signal relay. Labeled part number 2 in the following schematic:

Normally, same relay for both left and right side activations... Can't say for sure in your KZ... PO re-wring what ever....

These old KZ relays use current sensing so if you have a bad bulb, will stay on thus no blinky....

Check/repalce the bulb itself and check for grounds....
Front & rear bulb/housings.... Spend $6 and repalce both front and rear turn signal bulb....

You could always swap bulbs with the good side but for $6, Hell just replace them....

Measure the voltage at the blinker when placed in turn operations... Should see on your meter battery voltage....
Possibly you have a large voltgae drop through the switch for that side.... Thus low voltage & low current flow through the relay....

OMR

I switched the bulb with one from my parts bike but who knows how old that one was. It did the same thing. But then I bought some new bulbs since it seemed like the easiest fix and that was it. thanks for the info.