i need help "plz.." 2004 buick lesabre has some serious electrical issues going on lights, door locks work when they want fuel gage doesnt work engine lights go on and off security system light goes on trac light airbag light ect. and when the band button is pushed some of the issues start working right but not for long but if u disconect the battery it goes back to normal but that doenst last long either plz help

guess i would start cleaning grounds and the battery terminals, you notice any fluctuations in battery voltage?

No fluctuations already cleaned what I could the batter is under the back seat

those cars like to leak around the sunroof and take out the ground connections under the carpet and sometimes the circuit that connects all the modules. the stuff that you can "get too' is only a fraction of the connections on that car

Weak connections and battery can be the route of all electrical gremlins/evils.
Have your battery load tested with a good tester. Luckily I have a local shop that has a Midtronics exp 800 hand held load tester. My 800 CCA Delco battery read like 440 CCA and low on voltage, I had all kinds of gremlins then.
I installed a sealed Odyssey PC-1500 DT and used the top posts for better connection.
This battery load tested new at 1219 CCA!

Load test: Midtronics EXP800

Let there be real power and you will never get corrosion on terminals with this battery, and if your battery is under the rear seat you wont have any venting into cabin from this sealed absorb glass matt technology battery.
Odyssey is the best ,I expect 10-12 years of service life from it.