i have a problem with my battery crappin out after 30 or 40 min if the cars not on. the alt works but if my car is on too long like 1 or 2 hour the battery does it then to any know what might be wrong i dont think its a short
Take it in to Checkers, O'reilly's or Auto Zone. They'll check the battery for you and also do a system check.
If your charging system is in proper working order and your battery is definitely good:You may have an electrical draw on the system pulling the battery down.If it only takes 40 minutes it must be a big draw.disconnect your starter/alternator from the system and let it sit... if the battery is fine after a few hours its one of those components.Make sure the battery has a full charge before you do this.Sounds like a charging system problem or bad battery though.Check your cables/connections and grounds first.make sure they are All good/tight and clean.Good luck.
every thing is clean and tight and the battery is new so ill check the starter and alt again thanks for you help
if the alt has bad diods in it, it will drain the bat when the car is off and charge when on. take off a batery cable and put a test light in between the cable and batery. if the bulb does not blow then proceed to disconect the main alt cable. the light shoud turn off if the alt is bad. if it stays on then start pulling one fuse at a time. when the light goes off, then check every componet on the fuse. usually just unplug them till the light goes off.