Electrical problem

I have a 96 Pontiac Grand Am with an apparent electrical problem. Even with a new battery, it dies on me. If the jumper cables are attached, it will run fine, but as soon as the cables are disconnected it dies. Is it even worth my time and money to find someone to fix it? Any clue where the problem may lie?

Tow it to a shop and let them install a new alternator.

We had the alternator tested and its good. Any other ideas on what the cause might be?
Thanks!

If the vehicle runs fine with the jumper cables you have a charging system problem. If the alternator in fact tests good you have a wiring problem. The electrical current created by the alternator is not reaching the battery. Start by checking the Alternator fuseable link. I have attached a copy of the wiring diagram so you can see where it is. Also make sure the battery light on the dash is functioning.
~Michael

A lot of charging systems depend on the warning light in the dash to be working since current is supplied through it to the exciter in the alternator. If no power gets to the exciter then you have no field to build a charge with. Make sure the light works when you turn the key from ‘Off’ to ‘On’.

The electrical circuit is being completed through the jumper car, or battery. The battery cables aren’t completing the circuit through your car’s battery. In short, disconnect both battery cables, scrape inside the battery cable loops, scrape the battery posts, reattach. Try start. If low power, the battery needs recharging.

Thanks for all the help and the diagram. We’ll look into it. Do you think its worth it, moneywise, to fix it?