In this diagram link, you can see fuse 8 in the 3rd page down.

http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=28938

Here's the diagram after the switch. It's obvious it's after the switch since the fuse only blows when you pull the switch out correct?

http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=71347

As you can see in the diagram, the brown wire spreads out and feeds the truck from front to rear. Your only hope of finding the problem is to make educated guesses of where to look for the problem.

Most of the time the problem is in the rear around the bumper where people modify the wiring for trailer plugs. Another place to look is any added stuff with lights like running boards and such. When people add wiring they are sometimes not too careful how they run the wiring and it gets damaged.

Also think about when the problem started. Did you or a shop just get finished doing some work to the truck? Install a radio? Exhaust work where they could have melted some wiring?

If you can't turn up anything, you are going to have to start hunting some of those wiring plugs shown in the diagrams. So you can then isolate parts of the truck and see if the problem is in the front, the rear or some other part of the truck.

 

It started out of the blue last night. I jumped the #10 and #12 pins on the C273B connector....Power (#10) to exterior lights (#12), to check the switch...#8 fuse blew again.

I think I will find the connector for the flatbed harness, unplug, unplug the brake controller and see what happens then.

Thanks!

 

Got it.

I isolated the short to the aftermarket harness for aftermarket flatbed. I laid under the truck for about an hour to removev the harness. I looked and looked for a bare area that would be be the problem. Found nothing.

Tested the signal side to the ground side...still had continuity even though it should not have. Decided to just burn the spot where the short was, using a booster/charger. Well, I found the short, inside a molded connector. Cut the connector off, installed a new piece....life is good once again.