Blinker not working on 1980 K20

[willem445]

So I am trying to get my truck street legal and have been working on getting all the lights to work. I have yet to wire in the rear tail lamps after putting on a new bed. So far I have the fog lights and head lamps working. The passenger side blinker works correctly and the arrow lights up and clicks in the cab. On the driver side the light doesnt work and the in cab arrow doesnt light up or click. Any ideas on whats wrong here? I quickly tried replacing the wire going to the blinker as the wiring is quite old but that hasn't fixed it yet.

Thanks.