My battery goes dead overnight in my car, I made sure everything is off, I checked the connections, my altinator is good, I cleaned the posts, I even replaced the battery, but nothing has worked...Does anybody know what I can do Or check????

Try searching the 'electrical' forum for more info, there have been several cases like yours in the last few months.

If you have an ammeter or even a small 12V light bulb handy, wire it in series between the battery's (+) post and the (+) battery cable. If you do have something draining the battery the light will come on.

Start pulling fuses until the light goes out - that will point you towards the circuit that is causing the trouble.

The small amount of current used by the car's clock, stereo memory etc will not be enough to light up the bulb.

The job doesn't require any fancy troubleshooting equipment, just a methodic approach and a bit of time, chances are you'll find the culprit.

something has to be shorted or running...

when did this start happening? where you doing anything different or changing anything around the same time this started happening..

pull a fuse at a time and see if it stays up over nite, or put a DVM across the fuse holder and see if there's a draw with everything shut down.

Unplug the alternator and let it set overnight--I've seen many alternators charge fine, but kill a battery overnight.