Turn signal not working left side

[scenic760]

Hey all,

I replaced my turn signal column switch today and hoped it would solve all my problems, but hope is not a good strategy...

I'm still haunted house with my left signal not blinking... However when I turn on the hazards it blinks, somewhat dimmer than the passenger side though. I've switched out the bulbs with the same results.

The other issue is when I turn the headlights on, the dash left blinker in the cab stays lit. It did that before I replaced the steering column switch though...

The truck sat for a few years and I'm finding a lot of things have been cleared up by cleaning ground contacts (horn being one) but I'm not sure where to start on this?

Also, there is a solo wire under the dash next to the flasher just looking to be plugged in somewhere!?!

 

[75gmck25]

Most likely to be a bad ground at the tail light. Take both rear housings out, locate the ground wires, and sand the body to bare metal where it screws in. Then ensure the screw tighten up. There is also a larger gauge white ground wire for the rear wiring harness, usually grounded to the frame up near the back of the license plate.

Also ensure your black instrument panel ground wire is tight. On my ‘75 it grounds to a post near the top of the emergency brake mechanism, but on newer trucks they added a specific grounding bus on the firewall.

 

[scenic760]

Most likely to be a bad ground at the tail light. Take both rear housings out, locate the ground wires, and sand the body to bare metal where it screws in. Then ensure the screw tighten up. There is also a larger gauge white ground wire for the rear wiring harness, usually grounded to the frame up near the back of the license plate.

Also ensure your black instrument panel ground wire is tight. On my ‘75 it grounds to a post near the top of the emergency brake mechanism, but on newer trucks they added a specific grounding bus on the firewall.

Ok...after verifying all the grounds were good and cleaning them up the duck qucked in my face.

This is a bit embarrassing but it turned out to be a blown bulb on the driver side marker light!

Thanks again for the direction and I still don't know what that wire under the dash is for, haha!

 

[scenic760]

Ok...after verifying all the grounds were good and cleaning them up the duck qucked in my face.

This is a bit embarrassing but it turned out to be a blown bulb on the driver side marker light!

Thanks again for the direction and I still don't know what that wire under the dash is for, haha!

Ok...so everything worked in the driveway and took it out for a test drive and sure enough the left turn signal wouldn't flash..

I think I got all the grounds pretty well cleaned up and I tried hitting the contacts in the bulbs sockets with a small jewelers file too...I'm suspecting a loose wire somewhere?

Does anyone have any good tips for cleaning the socket contacts? Maybe a dremel?