Pontiac Repair: Dead Montana, jumper cables, pontiac montana

Question
My son has a Pontiac Montana, replaced battery, and ran fine for several days. Then when he pulled up to an intersection, the van died and lost all power, the dome light won't even come on. I had a good battery, and thinking that might be the problem changed it. Still has the same problem, but when jumper cables are put on it all the lights work well but when the key is turned all we get is a single click of the starter, it won't even offer to turn over, which is the same result we had with his battery. Even after charging the battery with cables it won't light up any of the lights when the cables are removed. Fuses seem fine. What could it be?

Answer
Hey Lee:

you have a connection issue going on here. the fact that jumper cables powers up the van is the key. either a corrosion issue between the battery and cables or a bad cable. If the original battery had acid leaking out one of the terminals on to the cable may have been the culprit for the corrosion. That is a pretty common issue on side post batteries.
Good luck :-}