2003 Cadillac CTS

You need to have the electrical parasitic drain checked. It should be around 20-30 mA maximum. This is done with an ammeter hooked in series with the battery cable. It is best to disconnect a battery cable(makes no difference which), and place a jumper wire and the meter across the open, then remove the jumper. This directs the current through the meter. The meter is usually fused, and the initial connection of the meter only, might blow the fuse, that is why the jumper wire is used, it acts as a switch. After you get a stable reading, usually about 20-30 minutes, you can determine if something is drawing excessive. If it is excessive, you can remove and replace one fuse at a time to determine which circuit is drawing. Keep in mind that your meter is part of the circuit, so opening doors, turning lights or key on, etc will blow your fuse.