the gremlin in my 84 f250 is causing me to hit this forum again.
the r. rear signal, brake, hazard light works, and then, doesn't work.
I have replaced the brake switch ( wires were messed up some)
replaced the bulb( with the correct bulb)
cleaned the contacts in the socket.
traced, checked and cleaned any splices on wires.
tested with test light both sides of multi connector under rear frame.
examined the 10 wires on steering column, wrote down color code and what it goes to.
this is a non tilt, manual, 4x4, diesel. all the other lights and indicators work fine.
right side running lights fine.
this has been going on off and on for a while.
I am replacing r. rear socket on general principles.
maybe need to do something with the turn signal switch?
it seems stiff, dirty. can I just clean it, or better to replace it? ( yeh...pull steering wheel, ok)
anybody else had this kind of problem, solution?

 

Yes I had this problem. it is most likely behind your steering wheel. I bought a puller for $10 at a local auto parts store. its super easy and self explanatory once you get started. you may find bare exposed wire where the insulation has rubbed off by the steering wheel. this will short out the lights. wrap with tape and good to go. or check your turn signal switch , it may be bad.

 

that was one of my thoughts, too. seeing from the photo of the unit, how it's put together. not to mention the fact this critter is 31 years old...
it has been raining here, and we just saw water dripping from the top of the windshield right into the steering wheel and column... you think?
so...o'reillys rents pullers and rock auto has the switch. fast glass the windshield. ( gaskets are no doubt dried out and cracking) bandaid a bit of silicone up there until the windshield can be dealt with.
thanks, etone, for your ideas.:

 

I would also check the ground connections for that bulb, but what Etone is describing seems to be a likely culprit.

 

You can try wiggling your blinker switch next time it happens. Maybe its time for a new one.

Mine comes and goes sometimes. Wiggle it and it works

 

getting a puller at our parts store for $10.00.. good thing to have on hand. open things up and really eyeball it.