2003 300m battery wont hold charge dealer said something was draining down charge dealer has had the car 3 days still cant find find why the batter is not holding new batter

Sorry but find a mechanic that isn't an idiot,( oh- maybe your mechanic does'n know about batter - you might need a chef )

I HAD THAT CRYSLER IN TWO OTHER GARAGES THEY COULD NOT FIND CAUSE NOW IT IS AT THE CRYLSLER DEALERSHIP FOR 3 DAYS CANT FIND WHAT IS CAUSING BATTERY TO DRAIN DOWN NEW BATTERY

Mechanics generally make poor electricians. You have a circuit that is draining power and it could be anything from the glovebox light staying on when it's closed to a bare wire. You need someone who can read a simple electrician's multi-meter to track down that circuit and sometimes finding the short (even after you have identified the circuit) isn't easy. In a pitch dark room you can close all the car doors and see if you see even a glimmer of light coming out of the ashtray etc., but don't expect it to be that easy. I had a car where I knew exactly where the bare wire was but I would have had to rip the car apart to get at it or run new wires ( and that would have also involved ripping apart because you don't want to splice a wire and just run it like a clothes line from a to b.) I ended putting in an . on-off switch to throw when I parked the car. Do you really want to pay someone $60+ per hour to check every circuit,then every piece of wire on that circuit then tear up the carpets or headliner to replace a 10 cent piece of wire? Good luck and hope it is just a courtesy light staying on when it should't be