on some cars the tail lights and brake lights are totally different bulbs gain access to the bulbs and have someone push the brakes so that you can determine which bulbs are the brake lights and replace the tail lights
98 sierra1500 4x4 all lights work excepttail lights fuses are good bulbs are new
make sure your bulbs are in the right way(tail light bulbs are polarity sensitve). Just remove the bulbs and twist them in the other way(you can do this with the lights on to check if the bulbs are good). Also, I know this is kinda simple, but check to make sure you plugged them back in (I've done it!)
Sometimes the bulbs have just blown, its not the wires as much as the bulb try replacing them with the spare bulbs in the box. But if thats not good enough then return them and get your money back! Simple as that!
Perhaps something in the gear shift that turns on the lights when in reverse position.
If the parking/tailight fuse is good - then it may be a bad headlight switch No tail lights but the bulbs are working? Please explain.
how can i fix lic plate lights not working when bulbs and fuse are good?
if the bulbs are not bad, it is the fuse, if the fuse is good, its the wiring.
check bulbs, fuses & reverse switch
It may be a back up switch located on top of transmission.
It could be the brake light switch (the switch that activates the brake lights when you step on the brake pedal) has gone bad
check the ground for the lights