Find the short in brake light?

[Grit dog]

So little advice maybe please?
Following my son in the 86, for a few minutes the lady brake and turn signal wasn’t working.
Then it started working again.
Checked bulb and socket. No amount of wiggling or tapping on the bulb made it go out.
Ground is solid and clean. Wiggled that wire too.
Didn’t crawl under and mess with the tail light harness plugs could be there. But those are also clean and dielectric grease when reassembled a few years ago.
Any likely spots for an intermittent short on a clean not corroded, not hacked up factory wiring?
Thanks!

 

[AuroraGirl]

So little advice maybe please?
Following my son in the 86, for a few minutes the lady brake and turn signal wasn’t working.
Then it started working again.
Checked bulb and socket. No amount of wiggling or tapping on the bulb made it go out.
Ground is solid and clean. Wiggled that wire too.
Didn’t crawl under and mess with the tail light harness plugs could be there. But those are also clean and dielectric grease when reassembled a few years ago.
Any likely spots for an intermittent short on a clean not corroded, not hacked up factory wiring?
Thanks!

is the 86 what your son was in or you
And what year is the vehicle (a CAN vehicle vs a 1990s will be different things to check)

 

[Ricko1966]

Play with the turn signal switch,and wiggle the wires at the base of the column while someone watches the rear. @Grit dog quoted me on post 5 read the quote,now you guys know why everything I post gets edited at least once. This one.twice already.

 

[Grit dog]

is the 86 what your son was in or you
And what year is the vehicle (a CAN vehicle vs a 1990s will be different things to check)

The 86 is the one with the issue.

 

[Grit dog]

Play with the turn signal switch,andvwiggle tge wires at the base of tge column while someone watches the rear

10-4

 

[AuroraGirl]

since you obviously checked the light socket out , you already checked the ground. id say verify your ground from the frame to the battery by the radiator and that the core support or fender to the battery are good and clean.

is there trailer wiring present? If so, if you have a magnetic trailer light set or if you have a spare trailer tail light , wire up to the turn/stop and tail and ground , set it up and follow the truck again. if the issue reoccurs , and both do it , youll know its most likely all upstream quite a bit like your column/switches

If you dont have trailer wiring or if you do and its just using a small inline T off the tail light harness , maybe isolating this from the list of things is worthwhile too and checking it for cleanliness at the same time.

 

[David King]

The yellow wire from the tail/brake lights go through the Turn signal switch in the steering column. My specific problem was that with the tilt wheel in the down position, the right tail/brake light would not work, with the steering wheel in the up position everything worked fine. My wife and I diagnosed this in the driveway! I ended up replacing the turn signal switch and now everything works fine. And yes, I swapped out the sockets, bulbs, and ensured all grounding points cleaned. Turn signal switch not a fun job but doable if you remove the bracket and let the steering wheel "hang down" from the dash board frame to facilitate removal of the electrical connector at the bottom of the column. Attach a pull wire to the old connector, pull it out of the column and then attach the pull wire to the new connector and pull down through the steering column, might want to bring a friend!

 

[CalSgt]

Attach a pull wire to the old connector, pull it out of the column and then attach the pull wire to the new connector and pull down through the steering column, might want to bring a friend!

I just snip the wires at the switch before I remove the busted one and use them to pull the new wires through the column...

ETA: @Grit dog did you ever figure this out?