Why do the lights and all electrical goes out when you turn key to start truck?

Seems to me that either the electrical ignition switch could have a concern, or the vehicle is not seeing the shift lever in "park" or "neutral" gear. If not in those gears, you will get everything to turn off as you turn the key to the point where the "start" function would otherwise engage. Test equipment checking shift lever position and circuit testing for the ignition system is needed. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops