Ok
So I took my truck down to the frame. All I need is my front bumper and my lights to work in the rear.
So my headlights work, markers work all in the front and on top.
Brake lights work, brinkers work front and rear. But for so reason my rear running lights don't light up.? Any idea why? Ty

 

Do the front parking lights work? Do the dash illumination lights work?

 

Tried new bulbs? LOL, probably a silly suggestion but that's the first thing that came to my mind.

 

Yeah after you check obvious stuff like bulbs, sockets, fuses. I would just start chasing the wires forward toward the cab. If I understood right, you have the bed off so this should be relatively easy. Use a multimeter to test for power at different points along the way. A wire may have been pinched or chewed somewhere.

 

Bed is back on.
-headlights work
-parking lights up front work
-brake lights work
-blinkers front and back work
-cluster lights work
-reverse lights work
So if my reverse lights and blinkers in the rear work...it wouldn't be the bulbs. Correct?
***also my license plate lights DONT work.
Does the multiethnic function switch have anything to do with my issue?
Ty

 

Could be the bulbs. The rear bulbs behind the red lenses have two filaments. The bright filament comes on with the brake lights, the turn signals and the emergency flashers. The dim filament comes on with the parking lights (aka taillights). So the turn signals working does NOT mean that it's not the bulbs. It could be that the bright filament is good, but the dim filament is burned out, on both.

Are you sure you have the correct bulbs, 3157, in those sockets? A 3156 bulb will work on the bright filament (brake, turn, etc), but it doesn't even have a second filament, so it won't light up with the parking lights.

 

what do you mean by the multiethnic switch?

 

$3.49
Two bulbs. Problem solved!
Didn't realize the bulbs did both.
Ty

 

You won't find too many repairs that cheap!

 

He meant multifunction switch in the steering column. It's connected to the turn signal lever and does lots of different things.

 

One time that switch went bad in my 96 f150 and it made my cel and abs light come on... None of my lights worked either lol...