brake light goes dim

my left brake light gets really dim when i hit the brakes, the running lights and blinkers work fine. i thought the running light and brake light used the same bulb? and i replaced it with no luck. i also thought there was only one fuse for both brake lights, or is there a fuse for each that may be bad?

sounds like it could be a ground problem. Check the grounds at the taillight area for loosness, corrosion, or bad connection. Hope this helps some.

late

i checked the grounds around the taillight and everything seems to be fine, i haven't followed the wires up underneath the truck yet. so its not a fuse?

not usually a fuse related issue when the light goes dim when braking. Have you checked the actual bulb and socket to make sure there is no corrosion built up in there?? still sounds like a ground issue to me, but I have seen some strange things in the past.

Late

sounds like short, low voltage of course it could be the ground, or the postive maybe open or touching somthing it shouldnt.