91 S10 rear lighting problem

the rear lighting on my 91 S10 is acting strange. I pulled the bed off it to replace the fuel pump and put it back together and my tail lights will not come on unless you turn the turn signal on. The signals do not flash anymore. The headlights low and high beam work, so do the brake lights and parking lights in the front. the emergency flashers work. the only ground wire I can see is right where the rear tailight harness plugs together. I looked for any bare wires that may be causing a short, but can find any. None of my fuses are blown??? any help would be appreciated. thanks

Check the tail light connector. You may have bumped it while removing the bed. It probably is not a short because then the fron turn signals wouldn't be working, and most likely would have blown a fuse.

I took the rear light harness off the truck and tested it on the ground. All of the bulbs worked fine when you put 12 volts to them. That is the only connection after the wiring comes out of the fuse box, it runs from the fuse box and goes back to the taillights. The only other connector on that harness is for the fuel pump, and it works fine.

Make sure you don't have any wires crushed between the bed and the frame. Something happened when you put the bed back on. check from the cab back thats where your problem wiil be.

i had similar problem w/ mine. i had crushed wires for tow package but it blew my fuse, then i had another problem w/ no fuse blowing, but one brake light would not come on (not bulb). follow the wires from light bulb forward and i bet your problem will seem obvoius.