Two problems related to battery cable have been reported for the 2009 Chevrolet Silverado. The most recently reported issues are listed below.
Locks started locking/unlocking. Gear indicator was going from drive to park. Heat came on by itself and fan went from high to low. Speedometer went from 70mph to 55 mph with loss of engine power. Headlights were flashing on and off. After pulling off I-75 and getting to a safe stopping area the truck would not start after turning the the engine off. The engine compartment felt extremely hot: especially the battery. After 10 minutes, the truck was able to start and continue the rest of the trip. After doing some internet research, this problem is well documented on various chevy forums and and car message boards. Replacing the mega fuse and battery cables appears to solve the majority of the issues as it did in my case. The defective mega fuse and battery cables caused the excessive voltage through the cables, causing extreme heat which resulted in scorch marks on the terminal ends of the battery cables and the insulation of the cables changing color as well as the above issues. I am very grateful that an electrical fire didn't happen which I believe could have easily been the case.
Several times while driving at various speeds the stability control warning light would flash, the door locks would cycle and the gauges would stop working. After a few seconds the warning light would go off and the truck would return to normal. I took the vehicle to the dealer and I was informed that both battery cables had high resistance and needed to be replaced. It is ridiculous that battery cables need to be replaced at 62000 miles. The service adviser made a comment that this was a common problem but it usually happens while the vehicle is still under warranty.