Pontiac Problems? Ask a Mechanic for Answers ASAP
Disconnect the negative battery cable at the battery and place an ammeter inline with the disconnected cable so the negative test lead is pointing toward the negative battery post, then turn the dial to dc amps. Now, make sure the key is off, doors closed and hood enough to put out the light and wait 30 minutes for all the modules to go to sleep, then read the meter. The draw should be below 50 mA. That's 0.050 amps. If it's over that, there is a problem, so begin pulling out each of the fuses and checking the meter after pulling each one to see if and when the meter drops below 50 mA. If it drops some but not all, make a note of which fuse it was and keep going, cause you may have more than one draw. When you find out which fuse it is, let me know cause then you would have to find out what on that circuit has the short and you can start by removing the ammeter, hooking the battery back up and seeing what don't work on that fuse's circuit, then use a voltmeter and trace the circuit to find out where the short in the wiring is. If you must keep the door open in order to pull fuses, just push in on the door jamb switch after pulling each fuse. You might also want to rule out the alternator first, so disconnect it first.