l changed the battery and altinator and the new battery went deadcan anybody help mewhy did the new battery go dead if l changed the bat and alt

could be a short in the wiring somewhere or an accessory that is staying on and constantly draining your battery. Did you have your alternator checked before you replaced it? That might not have even been part of the problem.

Check your voltage regulator ( its a little silver module on firewall of car ) l have had a couple of Lincolns that have had the same problem. The part is only around 15.00 at your local auto supply store.

About half of life is problems require a volt meter to solve. Volt meters cost about $5 for a cheap one. l bet you're glad you saved that $5 now. You would not want to waste it.

With a voltmeter you will be able to determine whether your charging system is working or not, and how well it is working. Then, when your battery goes dead, you will know whether it was caused by the failure of the charging system or by a power drain somewhere.

you might have an open ground some where check that all your lights are out even glove box and tighten ground wires under hood and on the inside of kick pad behind of emergency break peddle, hope this helps.

Have the voltage regulator checked.

something ran your battery down check for something left on the most common on these cars is the rear interior lights that can be turned on by a switch in the rear. If not the obvious then start removing fuses out of the fuse panel just keep track of what you remove. If that does not work then you will need to get a voltage meter.