Why won't my battery hold a charge ob my 85 Buick LeSabre?

Answer 1

more information needed (e.g. does the battery hold a charge when not connected ?)

if it doesn't it has a dead cell or is low on electrolytes

does the battery throw a spark when you connect the negative wire without anything on?

does it hold a charge for a short time or long time i.e. can you not start the car after an hour or does it take four hours to become un-startable?

the longer would indicate a device or relay not turning off thereby draining power

the shorter would indicate a bad alternator or charging wiring

if the charging system checks out i would pull out the relays one at a time (key off for this test) with a voltmeter connected to the battery when you re-insert the relay watch for a voltage drop this could indicate a stuck relay