jeep dieing

[blown XJ]

so my jeep has been dieing the battery dies.. so i got a new battery and it still did it.. i got the new batter cause it has sat in the cold for a couple months.. then it crapped out again i had it tested they said alternator i put a new alternator in and it died on the way home.. someone at school said that i prolly fried the alternator trying to charge the dead battery.. any help on what could be wrong

[Bounty__Hunter]

Could be a bad ground, I'd check and clean all the grounds.

[zafirex]

In addition to a ground, a short any place or improperly hooked up electrical component could do that.

Have had two problems that caused that with my jeep:
1. Frayed cabling to battery rubbed against the metal body, causing a short.
2. The used car dealer I bought the jeep from hooked up the cheapo car stereo wrong, causing a short and constant battery drain. Battery would jump and hold a charge for three days, but not a week.

Did it die while you were driving (had already started up), or did you turn it off and then it wouldn't turn over again?

[MudderChuck]

What year XJ?

[dandoc]

To test for a bad alternator:
-Start the vehicle's engine as normal and allow it to idle.
-Remove the negative battery cable from the battery.
If the engine stops upon removing the negative cable, you've got a bad alternator.

The battery is used to start the engine and to support the alternator's current to the vehicle's electrical accessories. A good alternator can support the engine and some accessories (up to it's rated amperage output) without a battery in the circuit. It'd be a good idea to check all ground wires for broken/cracked insulation, broken wires, and tight connections that make contact with bare metal. It may be teadious, but could likely save you money that you'd otherwise spend at the repair shop.

[blown XJ]

its a 1989 jeep with a 4.0 it will start and run for awhile till the battery dies driving down the road it has a new alternator in it now..