2006 denali 5.3l 2 wheel drive. Drove my grand babies to school Friday morning as usual with no issues whatsoever, 25 miles round trip. Got back home, then 30-45 mins later decided to go on another errand and the Voy would only click, no other issues. All accessories worked with no problems. I could turn the key to start position and it would click once then not again click for a couple moments. Trickle charged battery for approximately 12 hrs till light on charger turned green. Then it would click every time I turned the key to start position. So tried jumping it off another vehicle, no change. Pulled the battery from the running vehicle and swapped it into the Voy with again no change. So WRESTLED that *#&'&"$ starter out and took it down to be tested. Starter tested good with no issues. WTH??? What's next??m