If you have an ammeter, put it inline with the ground cable instead of the test light. On vehicles with an ecu and stereo, you should get no more than 50 milliamps (.050 amps) of current draw on the battery. Older toyota trucks don't have to many "always on" accesories, so look for items that should be off, like dome lights and glove box lamps. You can also use the test light trick across fuse terminals of suspect circuits.
