Had to jump start my 2008 Expedition with 90K miles. Figured the battery was bad. Took it to Walmart since it was a Walmart battery and it tested good. Took it to Autozone and the battery tested good as well. But, Autozone tested the starter with the same gizmo they tested the battery with and the starter tested bad. But, the car starts and runs fine now. I have started it 6 or 7 times now. Is there any validity to the Autozone starter test?