2001 Chevy Truck Truck may or may not start

About a week ago we had very bad lighting in my area. The next morning my truck would not start. I noticed when I turned the key my gauges were not moving either. After about 2 days it decided to start when I held the gas to the floor. Once it started it ran fine but I had no speed Od, no rpm, no gas, no temp, p, r, n, d, or odometer, we put in new ignition harness did not make a diffrence and my mechanic said he tried to scan it today and that It would not reply or that it could not be read.