well my wife was driving my truck on Sunday from Iowa to Colorado, after 2 hours the battery light came on, she made it home then shut the truck off. I turned it back over later that night and the light is gone, I took it to GMC to see what the issue was and the altenator is on the low side on putting out juice. Now today I went to get gas, I was at 1/4 of a tank. After I filled it up the gas guage said low fuel then started climbing up, then it would go all the way down again. Finally when I got to work the gas gauge was ok. Now can the since the altenator is going bad can this affect all the electrical sysetms in the truck? like the fuel issue I had today?

yes it can, remember, the battery is only on your car to help turn your engine on for the first time, after that, the entire car relays on your alternator, i had a similar issue but on a 03 n altima and all my instrument and panel light will dimm and act wacky because the alternator is not providing enought electricity for the entire car, take care off the alternator issue before it damage other parts. hope it helps

look like your charging system is defective, some time the alternator does not keep voltage high as ordered for pcm due to this extra needed volts will be taken from the batt it self and hen the batt volts out the engine will shutdown its like when you start up the engine without the belt on , it will start and keep starting and its die , fix soon or you gonna change the batt as well

our gmt 360 has smart charging system to protect the batt and extend it life