WHen the truck ignition is in the run position I'm getting 4.5 volts to the start wire of the solenoid. I can unplug the solenoid and jump the solenoid out and it will start and run fine. When I plug the S wire in, the engine shuts down. Leave the S wire unplugged and take the truck out of park and it shuts down. It has Distributor mounted module. HELP!!!!! Haynes wiring schematic not extremely helpfull.

 

Check your column wiring for a one wire shorting out to another.