having problems with my 1990 dodge 4x4 w250 cummins, the brake lights are not working.

tail lights work
fuses are good
bulbs are good/new

checked the sticky thread, my switch on the pedal is working, my trailer brake controller still lights up and works when i hit the brakes but get nothing at the bulb, also my turn signals do not work now either.

any commonly known problem areas im not checking?

thank you for any help/ideas they are much appreciated

 

Broken wire somewhere by the back of truck ?

 

Brake light power goes through the signal light switch before it heads to the rear of the truck, that may be a good place to start troubleshooting if you have a wiring diagram handy.

Also cycle your hazard light switch off and on a few times; that might help clean off the contacts if there is an issue there.

 

well heres a one for you to get a good laugh at the cummins noob

my truck is missing the emergency flasher relay causing my flashers not to work, well i had hit the switch for the flashers and did not realize i left it on because they do not work. well that caused my brake lights/turn signals to not work, i just went out and hit the flasher switch and bam my brake lights work again

thanks again for both your input

 

The old addage says you can't fix stupid. I guess there are exceptions.

 

You would be surprised at how often I've actually seen that! Glad you got it going.

 

Funny, but right up until you admitted "noob-diocy" I was going to suggest something was wrong in the multi-function switch.
I wouldn't have been far off.

Glad you got it fixed.

Mark.

 

Im having a similar problem except when i turn my head lights on they don't work

 

Sounds like the usual ground issues. Your tail lights probably don't work right, either.
Have someone else step on the brake and see if they come on slowly and look dim when they step on the brake. It'll look like a cold candle when you first light the wick, dull, then slowly come on a bit brighter.

What's your wiring at the rear of the truck look like? Splices and scotch locks, by chance?

Mark.

 

Sorry i meant my tail lights won't work if my head lights are on and we have tried tinkering with it a little but still nothing so hopefully this weekend we can figure it out!

 

I stand by the ground theory.

By the way...
WELCOME TO DTR!!!

Mark.

 

ok I'll try and see maybe I missed something! Thanks for the welcome!

 

What's yer truck. 1 ton, for instance, has a lot of load on the tail/clearance lamp contacts in the headlight switch, and can take em out.

 

As a couple guys already stated…. it was my hazard switch. My hazards have not worked since I got my truck earlier this year. I had already had this issue but today I had a brain fart. I even went to the Pick A Part and got another brake switch, brought it home and put it on. Still nothing then I read this forum and remembered to try the hazard switch. I pushed it several times and then the brake lights worked. I would advise everyone to hit the hazard switch a few times before you tear into the truck.

 

It sounds like the issue might be with the wiring or a connection. Since the brake switch and trailer brake controller work, it could be a problem between the switch and the brake light bulbs. Check the wiring for any loose or damaged connections, especially where the wires go to the brake light bulbs. The turn signal issue might be related to a bad turn signal switch or a grounding problem. Make sure the grounds for both the brake lights and turn signals are clean and connected properly. Also, check the bulbs to see if the sockets might be corroded or dirty.