The alternator was bench tested 5 times at two different stores all of which came back as "Pass". Put it back on the truck to have it tested under a heavier load and with engine on and it came up as a bad alternator. Bought and installed a new one BUT there still is charging issues. At idle voltage is just below 12v but under acceleration and cruising speed it maintains normal level (just fyi this is off the gauges on the dash). Again all connections and grounds are good and cables look good. Also, the CEL, TRAC off, and VSC light came on. Turns out there is a P0101 code which I think is an issue with the MAF. Gonna take it in and have a charging system performed and have a diagnosis done too. Any thoughts?