This is a new problem that has occurred with my 2015 Chevrolet Silverado with the 5.3 engine. Sometimes when I go to start it with the key it will not crank. This occurs primarily in the morning after sitting all night, but sometimes it will do it after sitting 2 hours. It doesn't crank slowly - it will not crank at all. There might be some clicking, but not like a starter engaging. If you switch the key off and on a few times it will eventually catch and crank. I don't know if the monentary current flow is sort of energizing the battery? I did put a new battery in the pickup and no change. Voltage gauge generally reads 14 to 15 volts driving down the road. Once in a while it will show around 10 to 11 volts. One morning when it didn't start I threw the charger on it and the charger said the battery was at 77% charge. I have put the charger on it 3 or 4 times in the morning and it always starts after several minutes of charging at 10 amps. For what it is worth I did get a free alternator test at O'Reilly's and Auto Zone and they both said it was fine. Didn't know if it was common for the switch to go bad? I assume there is a little starter relay in the fuse panel as well. Maybe the starter solenoid is going bad. Lastly maybe there is some kind of current draw pulling the battery down. Anyone have this problem and where should I start first. Hate to just start throwing parts at it. Thanks.