My son has an 04 Grand Cherokee with about 170K miles on it. He has gone through four batteries in the last six years. Today he tried to start the car to go to lunch and there was absolutely nothing. No click from the solenoid. Nothing. He got a jump from his brother-in-law who works with him and it fired right up. Took the truck to WalMart where he bought the last battery and was told the battery tested good. When he went to start the truck at the end of the day, nothing. He got another jump and headed home. On his way home he said he took a right turn and was accelerating and all his dash gauges went completely nuts. He says the voltmeter is showing swings between 12V and 16V. I was talking to him on his way home and we surmised it might be a short somewhere in the charging system that is draining the battery. The right turn scenario would tend to support the short theory, with the shorted wire touching metal as it is forced over by the turning G force. He tried to restart the car when he arrived home and it is dead again. Sounds like he was running on just the alternator. He said he can see the negative cable and there is exposed wire at both ends. He's going to pull the battery, have it tested out of the car, and buy new cables. Any suggestions of some other obvious things that we might have overlooked or that are a common problem with 04 Cherokees?

Could be a bad ground somewhere check all the connection and make sure none are loss or corroded, also could be the alternator going haywire on you

Before you spend money on new cables, try just replacing the cable ends. Those molded lead ends sometimes lose clamping pressure or get corroded where the wires go into them. It's not unusual for voltage to spike when there isn't a good battery ground.