hello, even though this is my first post i have been reading this forum for a awhile. and there is a ton of good info and good people here. my problem is my truck has no brake lights. i have turnsignals, hazards, running lights. but no brake lights. i replaced the brake switch activator at the brake pedal with one from napa. still nothing. help! its a 1996 ram 3500 auto 4wd with cummins and 331,000.

 

Welcome to the site.

The first thing you need to do is make sure you have power to the brake light circuit of the brake light switch. There are 3 sets of contacts in that switch, and I don't remember which ones are for the brake lights, so you may have to consult a diagram. Anyway, one of the 2 wires should be hot all the time, then when you depress the pedal, it should put power to the other wire, that goes to the bulbs.
From there, the brake light wire heads up to the multifunction (signal light) switch, where it splits off into two circuits and goes back to the taillights. The problem could also be in the wiring between the brake light switch and the multifunction switch, or the multifunction switch itself.

It's pretty easy to dignose if you have the wiring diagram. You can tell exactly which wires to focus on, and simply check for power at each point along the way. Without the diagram, have a good visual look at the wiring in these areas, paying attention to the steering column wiring. Disconnect the multifunction switch and check for terminals pulled out of the connector, and broken wires. Tilt steering flexing these wires can damage them over time.
Hope this helps a bit.

 

yes it does help! where is the best place to get a wiring diagram for this issue?

 

Geno's garage has the complete factory service manual on CD for only like $40, which seems like a great deal. I don't know if some of the aftermarket manuals, like Haynes, would go into enough detail to provide wiring diagrams. Someone else may be able to suggest where to find the one or two sheets that you need for this job.

 

Got it fixed, broken wire under the bed. thanks for the help!