2000 tahoe limted shuts off

I have a 00 tahoe limited with 63,000 miles sometimes when you start it up it bargs down but if you give it gas it stays running until you depress the gas pedal. It only does that every so often also when I turn the ignition switch off sometimes it kills all the power I have no idea why and it makes a ticking sound right below the steering wheel and at that time you can turn the switch to try an start the truck an it will not say or do anything. An it will still be ticking even if you take the key out the switch but once you put it back in an turn the switch forward the sounds stops in the run position and then the truck might start after waiting can any body help I would really appreciate it.:banghead:

Wrong forum. Try going to the Chevrolet forum and clicking on Tahoe. This is the Camaro Forum. :)