09-07-2011, 12:00 AM
Horn relay may be bad. Lpl wire comes with rear harness section. U should have hole on bottom of tailgate and another behind tag bracket wire is fished through tailgate. As far as a power source for splicing pull one of tailight housings out unplug it turn headlights on and see wgich wire has power. The other 2 wires are for turn and reverse. That may also let u know if you are even getting 12v back to rear lights at all.
If you can't fix it with a hammer and a welder then your gonna need a new one!