Completed all new hubs, bearings, brakes and checking torque of spring hanger bolts so went on shakedown highway jaunt. Plugged into factory 7 pin connector that is located in bumper instead of using the added female port located inside pickup bed rail. NO ISSUES; so, apparently, the after-market add-on plug-in, even though it appears to be a GM part, has a bad connection. Local automotive shop will take it from here and try to find the problem because I suck at all things electronic. Keep you posted.