So I'm trying to find out why my truck keeps dying. I jumped it off, let the vehicles run for several minutes, took the jumper cables off, and it runs for about a minute, then dies. I also noticed its idling weird. it will idle high, then get really low, then sound like someone is tapping the gas pedal. It will die soon after that. The alternator is brand new, I tried 3 different batteries (can't find my multimeter at the moment to make sure they are good, they are all about 5 years old). So I think I have it narrowed down to the battery, or a connection to the alternator. In the morning I am going to find my multimeter, and recheck the alternator connections. Am I missing something else that it could be? Would a bad battery make it idle like that?