These dash lights randomly and intermittently come on while driving or stationary. Chime sounds. Simultaneously, the tachometer and speedometer go to zero, and the A/C goes hot; A/C fan continues. A tap on the top of the dash over the display makes everything return to normal. (Photo in my album section)

 

I would tell you to swing into an Autozone or similar and have your battery and alternator tested. These trucks can do some really funny things with the gauges when the battery is not holding a charge well or is just dying in general.

 

I'll give that a try. I appreciate the tip.