2002 Silverado 1500 5.3L V8 w/ 219,000mi. On occasions my truck will not start. I put the key in the ignition and all the chimes and lights come on, my gauges light up and work, and the radio comes on. When I turn the key to crank, nothing. No clicking, no cranking, no nothing. Radio goes silent but the chiming still continues. When i return the the key back to the on position the radio comes back, my gauges still work and the lights are on. My volt gauge is reading between 12 and 14.I'll keep turning the key trying to start it several times. Out of the blue, without doing anything, it starts right up. Sometimes it takes several tries, sometimes it takes several minutes. But for some unknown reason, to me, it will eventually start. If the truck has been sitting for a long period of time, overnight, it will always start on the first try. Even when I leave from work and the truck has been sitting all day it will always start on the first attempt. Its when I'm running around to different places and the truck doesn't sit for long, like gas stations, restaurants, shopping, etc. It seems to happen most frequently during the fall and winter months. It hardly ever happens during the warm months. However, it is now happening on a daily basis now. I put in a new relay but the issue still occurs. I thought it was the starter but when i went to exchange it i had it tested and it was fine. they said i didn't need a new one. But I'm still wondering if it is the starter. Battery is new and in new condition. Any thoughts?