Image 5 of 7: To test for a current draw when the key is switched off, disconnect the battery cable, connect the black lead of the multimeter to the cable and the red lead to the positive battery post, and switch the multimeter to 15A with the leads plugged into the multimeter as shown. Our test vehicle is 50 years old, with no clock or electronic radio, so no draw is shown. A typical draw, taking these common accessories into account, would be .001 amps.