Yeah good point, the only other strange thing that goes on is sometimes (not often) if I turn the ignition key to the “run” position but don’t crank the engine, it automatically starts the truck. Maybe I do need to chase down some wires.
Electrically, this should not be possible on your year of truck without some electrical failure. You would have to have the white, pink, brown or orange ignition wires shorted to the yellow ignition wire, or have a short in the fuse box that jumps the starter relay off ignition or something. On the pre 2007.5 trucks the starter circuit is high current from the key, to relay, to solenoid to starter. Ignition and accessory are not a part of the starter circuit until the new trucks started after 07.5.
Based on this information i would take a look at your fuse box (under side of under hood, and back side of in cab) for any damage from mice / moisture ect. and id look under the driver dash for any signs of similar damage to the ignition wires. They should be 14-12 gauge wires running to the key switch and then to a bolted in connector near the BCM.
your ignition wires should function like this.
Red - Hot always
Red 2 (may have white or black stripe) - hot always
Pink - Ignition 1 - Hot in run and start
powers main engine ignition circuit
White - Ignition 2 - Hot in run and start
required, but truck will start without it, will damage transmission if not powered.
Orange - Accessory 1 - Hot in Run and accessory, drops out in start
NOTE: this is power to the HVAC system
Brown accessory 2 - Hot in Run and accessory, drops out in start
Powers wipers, radio, non critical systems.
Yellow - Starter - Hot in start position ONLY.