Has anyone had issues with turn signal lamp dimmer on one side than the other? my passenger side front turn signal is dim , could it be a bad plug,ground, or wiring back to turn signal switch

 

Yes to all. the plugs get corroded, grounds get dirty and wiring gets old. Would start at socket and ground, clean them up and see what you get.

 

Here is a good read X2

https://www.ford-trucks.com/forums/1...ml#post1812190

Turn and Stop Lamp Diagnosis for 70's Ford Pickup - Ford-Trucks.com

 

Short answer is yes....could be plug or ground. The headlight, side marker, park light and turn signal share a common ground connection. If they all seem dim, I'd suspect the ground. You could check the turn signal/park light socket ground to the battery Neg. terminal. The little ground tab in the socket to bat neg. should read around 20 Ohms or less on an Ohmmeter. High resistance points to a bad ground on the frame above and behind the headlight location. It is behind the flexible air dam stuff (follow the wires).

If all other lights common to that ground are bright, I'd suspect the blue/white turn signal wire. Check the voltage on the blue/white wire where it goes into the socket and again at the terminal that the bulb touches. A lower reading at the bulb contact points to corrosion on the tiny Molex type connector inside the socket. I had this on my Driver's side turn signal. Not having a Molex terminal removal tool, I just bought a new socket at the Auto Parts Store.