Common Problem? On startup, no power to radio/clock. Sometimes no power to start. Fix is to wiggle ground wire to restore power. Connection to block and battery pristine, but had mechanic clean & reattach. Perhaps relay? Happened again. One other thing - driving at 50, had a detonation just behind cab - like the hot-rods of the 60's. Truck ran well before and after! Cause perhaps short power loss? but no lights out.
Thanks in advance for any help. Truck only has 55k. - Peter

Truck: 2008 Silverado, 4.3 liter V6 2WD auto 55K miles

 

If you have to wiggle the negative battery cable to fix it, then your problem has to be in that area. Was there previous damage to the cable and battery from corrosion? If so then itn is sometimes hard to get a good connection. The cable or just the cable end would need to be replaced. Investigate further!