Blowing Fuse

Start by looking for a chewed up trailer wiring harness. Also check the wiring behind the rear bumper to see if there are any bare wires touching the bumper or body.

To prevent wasting a bunch of fuses, plug in a pair of spade terminals, then connect a 12 volt light bulb to them with a pair of jumper wires. For this application a head light bulb will work well. The bulb will be full brightness when the short is in the circuit. Be sure the bulb isn't resting against carpeting or plastic panels. Now you can unplug things and remove the tail light housings to see if something makes the short go away. When it does, the bulb will go dim and if you look closely, you might see the tail lights glowing very dimly.

If you have an aftermarket radio, don't overlook someone mis-wired the ground wire. A lot of people confuse the dash lamp wire or the tail lamp wire because they measure such low resistance to ground. They appear to be ground wires but they are not.

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