I've got a stock 98 ram 1500 with a 5.9, its got alittle over 150k on it, and has never given me any trouble until now. Now it just won't start. It starts fine when you jump it, but at idel as soon as you take the jumpers off it dies. I thought that its was a combo of bad battery and alternator, so I put in a brand new batter thinking that would tell me if indeed it had a bad alternator, but it did the exact same thing. W/o jumpers on it the starters not even engaging, when I turn the key w/o jumpers it clicks then buzzes.

Anyone got an anwser or suggestions.

 

sounds like battery cables..., check for any corrosion on the termainals. remember, when you jump a battery, your putting 2 batteries in parallel, which increases the current. I'll bet your not getting all of the battery current down to the starter when your not jumping it. Also make sure all of the grounds are good. there should be 1 ea at the back of each head and a big one on one of the power steering pump mounting points.