I have a 2006 Lariat with a 5.4L.
Some serious problems here.Earlier this week, my back up sensor decides to turn off as soon as i shift the transmission in gear and stays off.The next day, my A/C/heat instrument cluster decides to light up completely and not work.The next day it is off completely and won't turn on, including heated seats.Now, i try to start the truck and the alarm goes off(honking) and won't turn over.Anyone else ever experience this?

 

Now when I try to start it, the gauges bounce rapidly but not very high and the alarm goes off.Could it be the battery?

 

Yes, these trucks do some very weird things when battery starts weakening. If your battery is more than 3 years old, that is where I would start. The gauges bouncing around is a major indication.

 

Changed the battery, problem solved!!!!!! They sure do some weird things don't they????