Another blinker question
 

When I turn on the right blinker the red light above the speedo for the high beams blinks. The left blinker works fine any ideas what could be causing this?

Re: Another blinker question
 

Seems like a classic ground issue. That is really odd symptoms.
67-72 trucks have a dash panel ground that well, should be grounded.
Grounds from the front to the rear of the truck should be corrected. Yes, pain in the butt. But...

No one wants to know, but flashers switch by bending of a bimetallic strip. Heat generated by current flow makes heat; that bends metal causing a switching effect. BS is good. :)

Re: Another blinker question
 

I Checked the grounds in the front they are good do you know where the dash panel ground is?

Re: Another blinker question
 

The early models of these did not have printed circuits. The bulb for the turn indicator may be in the wrong hole.

Re: Another blinker question
 

I probably should have gave more info in the original post it is a 1968 c10 and it does have the printed circuit board I checked it. Thanks for the replies though I think Its a problem in the circuit board itself.

Re: Another blinker question
 

Did you figure this out yet? I’m having issues also I’m curious what you found out