[Legolas894]

Originally Posted by 71swb4x4

Sounds like you are grounding one of the power wires to a ground, maybe the frame?? I would check the harness from start to finish. Check both sides of the firewall plug and then follow it back to the crossmember plug and from there to the taillights and license plate light. If nothing there check it up through the brake light switch and into the column.

I would start by simply unplugging the plug at the firewall. If it doesn't blow, you can almost be certain that the problem is after that plug. Then unplug at the crossmember by the bumper, and so on and so forth.

x2 for this-unplug the plug, replace fuse and see if it blows. If it doesn't, it's the harness going to the rear. Mine was messed up with an old trailer light harness grounded to frame.

Longhornman helped me find that.