Turn the key, get 1 click, then nothing. Truck was running fine the day before. on 1999 Chevrolet S10

Have replaced the battery and the starter. Still get l click and does not start. Lights and radio work fine. What do I need to check?

Asked by for the 1999 Chevrolet S10
Check that the battery connections are clean tight and secure, make sure the ground strap to the engine and chassis is OK. Measure the battery voltage if charged it should be 12.6 volts, for the hell of it try jump starting it from another running car. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate