How to trace a parasitic draw

Use a multimeter (not a VOM). Put the multimeter in ammeter mode (<10A). Make sure to switch the common to the correct socket. Make sure the key switch is off and the key removed. Take off the negative terminal of the battery. Put your foot on the brake pedal to drain any remaining current in the circuits. Hook the red probe to the disconnected negative terminal connector and the black probe to the battery. Look to see if there is a current draw, any more than a milliamp or two. If there is not, revise your hypothesis and suspect the battery. If there is, pull the fuses and replace them one by one until you find the fuse that makes the number on the multimeter readout drop significantly when you pull it, then troubleshoot that circuit. Trace it backwards from whatever utility it runs, disconnecting connectors in sequence moving towards the battery, until you unhook the connector that makes the number on the multimeter drop. The faulty circuit is now isolated.