no brake lights

L

lews930

NOT A DIESEL PRO
Joined
Sep 25, 2008
Messages
751
Ok ive searched and read and had hoped I wouldn't need to do this but....

I have no brake lights. 4 ways and turn signals work. Brake controller doesnt work.
Im not getting power to the plug that goes into the brake switch.

I have power at the 20 amp fuse under the hood.

I need the brake controller to work as I intend to pull my 5th wheel to Snowshoe for some winter fun right after Christmas

Any help appreciated
 
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1st step is unplug the brake controller and check, I had one go bad and kill the brake lights. I kinda doubt it though since it requires a signal after the brake switch. I can't remember if the brake switch uses the hot leg or the ground leg to activate.
 
Lewis,
On a 2005 it is fed directly from a fuse from the battery box #25 and is a 15A. Grey with red tracer is live all the time.
 
Do you have a trailer plug in the bed of your truck ? Reason is I had exact issue on my truck, they had tapped the bed plug into the wiring for the plug by the bumper hitch with scotch locks, they were all filled with dirt. Replaced all scotch locks with better connectors and everything worked brake controller and brake lights.
 
Nope. No plug in bed. Only the factory plug on the back

Thanks though
 
There's two fuses. One in cab,one under hood. Take the brake switch out and inspect it. It may have gotten hot and shorted. I've even seen those wires going to that switch melt together. Good luck.
 
I'm only finding 1 fuse. A 20 amp under the hood

Again, I'm not getting power at the brake light switch plug. Its not melted either
 
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Ok. After a re inspection of the fuse under the hood I found it was bad. I now have power to the brake light switch plug!

However, I dont have brake lights.

The switch operates.

If I plug the brake controller in it blows the 20 amp fuse. Expensive testing procedure
 
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Check the fuse in the cab. Don't you have the cover that goes over the fuse box in the cab? That has the fuse map on it. You definitely have one in the cab.
 
I'm a wiring genius:) Tim, aka Mo smoke will get a chuckle from that

I found a scotch lock hidden in the brake light circuit. The brake lights now work but ive burned up so many of my fuses under a hood that I can't start the truck:hehe:
 
Lights yes but havent plugged the brake controller back in. I dont have any more fuses
 
Must have something in the brake controller wire rubbing or touching, causing it to blow, maybe bare spot in wiring
 
Or someone used scotch locks to wire up the brake controller. Scotch locks are bad news if dirt and moisture get to em.
 
Ok. I plugged the brake controller back in and bzzzz. Blew another fuse.

When I put a test lite on the factory female brake controller plug I have power at the big red wire. When push the brake pedal I get power across the white wire as well. I used factory dodge male end as well and wired color to color as I have done in the past

Not sure if thats supposed to happen but it blew the fuse
 
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You should have power out of the blue wire when the brake is pressed. That's for your trailer brakes. I would say that brake controller is bad. Edit: I read your post wrong. You should have power at red wire. Then power out of white wire when you push the brake. I still say it's the controller.
 
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