considering this car for a project btw i'd do ALL the work i mean parts
Drainage' is cheap to fix, once you find it. If it's just your time, (and you've got a lot of it), go ahead. It means isolating parts of the electrical system and patiently going over the wiring to find the 'leak'. (In a vehicle that old there might be a lot of frayed/abraded wire to replace because it's 'about ready to go'.)
Basics are: Remove fuses and relays one at a time to find circuit that is draining the battery. Refer to your vehicle owner's manual or a wiring diagram to identify the fuses and relays. Then pull the fuses and relays one at a time until the current reading drops. Avoid pulling the fuses for the PCM or other KAM-sensitive modules until you have checked all of the other circuits. Once you've found the circuit that is causing the excessive current drain, check the relay, switch, module or other components in the circuit and replace as needed. Sometimes a bad alternator diode can cause a battery to run down. A good diode should only pass current in one direction. If it leaks current in the opposite direction, it may keep the charging circuit on when the engine is not running, causing the battery to run down Causes of excessive current drain in late model vehicles include things like lights that remain on (trunk and hood lights, interior lights, brake lights, etc.) and also relays that may be stuck on, or modules that are not going to sleep or powering down. A fuel pump relay that sticks on may keep the fuel pump running after the engine is shut off. A switch or relay that powers a rear window defogger can stick on, pulling current from the battery after the ignition is off. An electronic suspension module, ABS module or keyless entry module may remain active long after it should have powered down.
