This happened to me yesterday, I had the alternator checked and it was fine, and the I got a brand new battery and it kept doing it, it ended up being wiring issues so get your wires checked most importantly the ground wire.
Weak battery? not holding a sufficient charge Alternator not charging battery sufficiently?
Dim All the Lights was created in 1995.
to warn the drivers behind your automobile that you are slowing down
If the back dash light will light when the brakes are applied but the two tail lights will not light up, there is probably a short in the wiring somewhere. It could also be that the fuse for the brake lights is burned out.
You should dim your lights as soon as you see their lights.
In the back should be tail lights which always come on when the headlights or parking lights are on, and stoplights which come on whenever the brakes are pressed. The stoplights should be brighter than the tail lights, but they should be separate.
bad ground on chassis. do the lights seem dim when you apply the brakes?
Bad ground, usually at the rear lights.
Fog lights are in the front; they are commonly referred to as "brights" because they are the brighter of the two standard headlights. Brake lights are in the rear; they light up when pressure is applied to the brakes or when the car is in park or reverse.
1989 silverado left turn signal set applying brakes causes the left turn signal to dim and the two right rear tail light bulbs to alternate brightly? Further problem occurs to same truck - in Park and brakes not applied -- if head lights are on turn signal flash slows right down almost to a stop and becomes very dim
wheel locks up and abs light come on because abs not working on that wheel lights go dim because alternator not working completely
How dim? There are several possible answers. First, the output of the light coil is directly related to the engine rpm. Second, if the regulator/rectifier is not functioning properly, the lights can be dim. Third, if you have a poor ground connection the lights will be dim.