1. Is this an auto or a manual transmission?

2. Equipped with cruise control or not?

3. Equipped with rear ABS or not?

4. Equipped with electronic trailer brake controller or not?

5. With or without factory trailer tow lighting?

6. Do your turn signals (may blow fuse F7) or emergency flashers (Fuse F13) work properly?

 

1. This an auto transmission
2. Equipped with cruise control
3. Equipped with rear ABS
4. Not equipped with electronic trailer brake controller, no trailer hookup.
5. Without factory trailer tow lighting
6. Do your turn signals or emergency flashers work properly? Yes, everything does except for the brake lights. Truck runs to.

I have the dash off. Fuse 13 blows when I press the brake. I traced it down to a connector in the center of the dash. When I unplug this connector the fuse won't blow. On the plug without power the wire colors are red, blue, green and white. On the light diagram for fuse 13, I don't see were it goes to these colors, am I right?

 

From my other post: Need a wire diagram. I have a connector in the cab that has red,blue,lt green,white end. It's connected to a Lt blue/wh stripe, Lt blue/red stripe, blue/green stripe, black end. Looks like factory wiring because of the stripes on the wires. I found the exact same truck at the salvage yard and the ( trailer) connector was attached under the ash tray, not connected to anything. Mine was wrap in the original wiring bundle, behind the ash tray. There's no way to reach it unless you remove the dash. I have the dash off at this time. I notice when I unplugged this connector my fuse didn't blow anymore. It is when the my brake lt green wire and the black wire made connect.

Franklin2
That sounds like the brake controller wiring the factory puts in the trucks if you want to install one to pull a trailer. It shouldn't affect the brake lights unless someone goofed on their trailer wiring.

I jumped one wire at a time on the trailer connector. The only one that blew the fuse was the LT green, to black which runs to the brake pedal. What's the purpose of the lt green wire at the brake pedal switch?

 

That is the stop lamp feed.

 

I found this on the internet, is this correct?
The stop lamp sends power from the brake pedal switch in the lt green wire to the ABS module, transmission ECA, EEC, besides the third stop lamp and brake lamp.

 

Does someone have a color ? diagram like this for my truck. TrailerAdapterFactory.gif gif by subford | Photobucket

 

I don't have your year truck's trailer wiring diagram. And part of the problem is they seemed to change it almost every year unlike some of the more common wiring.

I can tell you generally how it works;

You have a hot all the time fused power that feeds the brake light switch. I am assuming this is the fuse that is blowing.

Coming out of the brake light switch is the brake signal wire, and like you said it feeds the high mount brake light, the cruise module, the abs module and anything that needs this signal including any aftermarket brake controller and it's wiring. It also feeds the turnsignal switch in the steering column. It does not feed the brake lights directly.

When it goes up into the steering column it feeds the turnsignal switch. There is also another signal coming into the turnsignal switch; That is the flasher signal. The turnsignal switch is rather complicated setup which mixes the flasher signal and the brake signal together to feed the rear lights.

If your turnsignals work on both sides, that would tell me the lights and the wiring all the way to the turnsignal switch are good. I do not know what that wire is that you are unplugging.

 

I don't know if this helps. It's the lt green wire that runs from the brake pedal across to behind the ash tray. It connects to all the blank ground wires that are bundled together. When I disconnected it from the black wires, the fuse didn't blow anymore. All the other lights work. Thanks for the info. I'm learning a lot. I didn't know how to read a wire diagram before all this happened.

 

Well, you certainly don't want to ground that light green wire. Is this a project you inherited or just bought? This doesn't sound like a "everything was ok and then one day" type problem.

 

It ran fine for seven years. A mouse peed in the vents. I ran it for a while with the smell, I didn't know what it was. Then I found a empty nest in the blower. I removed the dash cleaned the vents. I noticed that I had bent the brake switch when I had lowered the steering wheel. I replaced it, ever since then no brake lights. Someone added a connector to the tailor connector. When I unplugged it the fuse stopped blowing. Looks like I don't need that connected anyway. I not pulling a tailor.

 

That is your problem. Disconnect and insulate it, then call it quits. You're making this much harder and more prolonged than it needs to be.