[casscam]

We put in a stand alone horn button with two connections, 1 coming from the keyed power and 1 going to the solenoid.
Afterward, Truck would not crank. Put a bypass wire to battery and it started fine.
Truck drove in limp mode.
1. How do we fix the start with the key
2. Why limp mode? Could it have anything to do with the anti-theft disengaged?
Stumped!

 

[casscam]

Problem Solved!
It was a U0073 code, the can bus. It affects how the pcm talks to all the other moduls. When the bus goes down even for a second and throws the code U0073. Sometimes the truck will not crank with it set because the transmission send its gear info to the ecu via this bus. If the ecu does not know that the trans. is in park, meaning it could be I drive it will not let the engine to crank. So clear the codes and it sets everything back to normal.
Could be a short, loose connection or wire in the can bus, OBD port sensor under the dash. Try unplugging anything that you plugged in and it might help troubleshoot what might be shorting out the bus.