On start up the low 4x4 and the park brake light come on. the alarm is ringing and lasts for up to 10 minutes before shuting down. Sometimes while driving this condition come on and it will kick off the cruise control. 4x4 does not engage while this condition is happening. I also noticed if the engine is under load, and the automatic transmission drops down to a lower gear the alarm shuts off.
any help would be appreaciated.

 

The only thing I could think of is maybe moisture somewhere.

Maybe try posting your question here.

Super Duty & Heavy Duty - Ford Truck Enthusiasts Forums

Probably give a little more help than me.