There are some areas I suggest you check during your troubleshooting, since they confuse many “mechanics” who may have tried to fix the truck in the past, and that leads them to bad wiring work-arounds.
- grounds are very important. A missing instrument panel ground will screw up most everything in the dash, and a missing lights ground at the radiator support or tail light will cause multiple exterior light issues.
-The ignition switch cylinder moves a small rack and rod on the end of the switch, which connects to the electrical part mounted much lower on the column. If the ignition switch does connect the electrical contacts correctly in each position (e.g., start in neutral and park) it may be the rack and rod is broken or misadjusted. That cheap ignition switch rack is a PIA to replace.
- the circuit for the interior lights and above-bed exterior light works backwards from other circuits. The circuit always has power on the orange wire, and they switch the ground using the door switches or headlight switch. This means that light housings cannot be grounded to the truck, and there may be insulators in key places. It also means the orange wire that runs under the sill plate and up the cab corner is always hot, so don’t pinch it in anything.
- you might be able to insert a dual contact bulb and mange to get it backward in the housing, so check that on the tail lights.
- if you accidently create a big short (battery cable backward?), the fusible link in the power wire running down from the firewall junction to the starter lug seems to go first. And sometime it doesn’t fry the outside insulation, even if the link is broken inside.
Gotta add peppermint, cinnamon, coconut milk, lighter fluid, kerosene, and a bunch of other stuff to kill the dirty sock taste of it...
