In my 1965 mustang I have one dim tail light when lights are on. Its the driver side. The bulb is good, The tail light is new, Anyone have any idea where to look.
Is the housing rusty? Or not as reflective as the "good" side? I was suprised with the difference when I replaced my housings... and painted them with a bright white for a quick fix
Is your lense a scratched/clouded up original? New reproductions do make a difference...
If the above don't apply or work, check the wiring with a dvm, and clean your grounds
Actually its pretty weird. I learned today with the flashers on the right (passenger) is dim, with the headlights on no flasher at all on the right, with the brakes on the left is bright, the right is dim, with the lights on the left is dim and the right is bright.
1) Take some steel wool and clean the contacts in both bulb sockets. Clean the sides of the socket so that it's bright.
2) Trace the wires in the tail light circuit that goes to ground. I think it goes to the brace at the fuel filler neck.
3) As said before, brighten up the bulb housing with some steel wool or even some high temp white or silver paint.
4) New lenses definately help.
5) Install a new flasher.