weird electrical problem please help

[57fordf100]

ok so my passenger side tail light when i hit the brakes lights up real nice but the driver side lights up but not so bright it seems like it stays a little dim also my front turn signals the driver side brights up real nice but the passenger side stays dim it brights up but no the same as the driver side what can be causing this problems and what can i do to fix the problem

[70_F100]

Sounds like a bad ground.

The other possibility is that the wires are reversed going to the lamp. When you turn on the parking lights, is one side brighter than the other?

[57fordf100]

yeah when i turn on the head lights all the lights turn on and thats when they dim could it be i have a bad ground or would it be the power going to it

[fordman]

probably a ground. trailer lights will do that to you also.

[rjewkes]

i have also had the p.o. wire in lights backwards so the turn side of the fillement lights when used as running. it could aslo be a bad connection cuased by the spring in the sockket is weak.