Starting problems

[AM0608]

Today I bought a 2000 Expedition XLT 4x4 with the 4.6. When I bought it, I knew it I needed to jump it to get it to start. It started fine once I jumped it, and I drove it around for about 30 minutes but then had to stop and get gas. So it started fine when leaving the gas station but nothing on the dash lit up or worked (speedometer, RPMs, temp gauges, etc) and the battery light was on. I pulled over and shut it off and it wouldn't start. I tried to jump it, once I hooked up the last cable to jump it the engine started turning over constantly without the key even in the ignition and it was not turned to on or anything. Then about 45 minutes later it jumped and ran fine but still had the battery light on. I hit the alternator with a hammer and the light went off. I drove it home 2.5 hours away and it was fine the whole time. I turned it off at home and restarted it and it was fine, anyone know what could be the problem in case it happens again?

 

[stamp11127]

Electrical connections. I'd go over the charging & starting circuits, load test the battery after a charge and load test the alternator.

 

[AM0608]

Ok I will check out that stuff tomorrow. Today when I drove it the CEL light went on then the battery light when on then off a min later but the CEL light stayed on. I will also scan it tomorrow. Anyone else have this problem?

 

[stamp11127]

Also check the battery voltage prior to starting and the charge voltage while running.