1999 Chevy Express 1500. Had a hard time starting during the winter months. Finally got a new battery and it started up first time. A couple of days ago the interior light was left on so the battery was completely dead. Tried to jump it from another car, and it would not start. Charged the battery overnight, and it started right up. Why wouldn't a jump start allow it to start? Not enough amps to trigger the fuel pump? Is there a short somewhere to not allow the fuel pump enough amps to pump?

 

Bad jumper cables with poor connector clamps will always make a bad connection and not supply enough power to start a car. Sometimes you have to move the clamps around on the battery terminals on both batteries to get a good connection.

 

What oldchevy said. I always look for a spark.

 

What stanvan said. you didn't get the cables on all the way, or loose connection.

 

I think the dead battery will be swallowing a lot of current, making it unavailable to the starter. Often when giving someone a boost, the car won't start immediately, and you have to wait a few minutes for the dead battery to recover. It also help to rev the assist vehicle a bit to generate more current.

As was already said, it helps to have have a good cables (4 AWG), and a good connection. You want as much contact as possible with the clamps. Negative on the dead vehicle: as close to battery as possible. On assist vehicle: engine block.

 

Check under the dizzy cap for corrosion. That and worn spark plugs cause weak spark which makes for hard cold starting......