no brake lights

[society909]

I just bouhgt a 2001 Dodge ram 3500 diesel pickup on the way home someone told me I had no brake lights so I stoped at Autozone and bought a brake light switch but it didn't help. All of the bulbs are good, I checked all of the fuses and relays I could find, all good. Than I found when I push the lever over on the trailer brake unit they came on, but they wont come on when I hit the prake pedal. Is this unit bad or what?

[Chris Stewart]

Try this,
INSTALLATION
(1) Connect harness wires to new switch.
(2) Press and hold brake pedal down.
(3) Install switch. Align tabs on switch with
notches in switch bracket (Fig. 3). Then insert switch
in bracket and turn it clockwise approximately 30° to
lock it in place.
(4) Release brake pedal. Then move the release
lever on the switch to engage the switch plunger. The
switch is now adjusted and can not be adjusted
again.
(5) Install the knee bolster.

[society909]

I already did all that as I said in my first post, but it didnt fix the problem. I know how to replace a brake light switch, but that wasn't the problem.

[NocturnalCreations]

Sounds like someone missed hooking up a wire. I would just hook the switched brake light wire from the switch directly to the brake light wire. Im not sure exactly how the whole trailer brake thing works but it sounds like the switched wire from the brake light switch goes to the trailer brake first and then to the brake lights. So it would be like making a jumper wire to bypass the trailer brake but the function of the trailer brake would stay the same. Or maybe the trailer brake unit is bad or missing a wire.

Im just guessing because I dont know exactly what the other brake component is.

[Chris Stewart]

Yup, kinda looks like the controller is keeping the brake light circuit open if the new switch was adjusted when it was installed.