Need some helpful advice. My 1999 silverado 1500 wont start. New battery shows +12.4 volts. The truck is an automatic with about 258000 miles. Transmission was replace at about 225000 miles. I have no power anywhere. Turn the key and nothing happens, no buzzer, dash lights, no security or waring indicators, nothing. The day before everything was find, however, I recharged my a/c unit (found leaky valve) last night, and today nothing works. I don't believe there is a correlation between the a/c the whatever is going on now, however, I could be wrong. I'm thinking the problem is the neutral safety switch but I'm looking for any solutions out there. I have moved the shifter lever to neutral and still nothing works. Its as if there is no battery in the truck. Any help would be greatly appreciated.

 

I'd be checking the ignition switch, if you turn the key and have no dash lights then your power supply wouldn't be making it to the neutral safety switch.