Join Date: May 2002
Location: Kingsland, Georgia
Dave, You can disconnect the negative battery cable and take a 12 volt test light and hook one end to the battery cable and stick the pointed end in the negative battery post or hold it there with your son's help.
If the light goes on you have a drain.
If the light is off verify the test light is good and hooked up correctly (good contact) by turning on something on like the parking lights. The test light should glow.
If he has a radio that requires a 12 volt power source all the time (for a clock or station presets) you will have to disconnect that wire because that will light the test light.
Now that the test light is hooked up and illuminated and everything you can see is turned off as far as you know, start pulling fuses one by one to isolate which circuit is causing the draw. The light will go out when there is no load on the circuit and that will be your battery drain.
If the fuses don't turn the test light off you may have to start disconnecting wires.
The brighter the test light is the heavier the load (drain) is.
This test will also work on computer controlled cars but there is a milliamp draw from the PCM so the test light will illuminate but it will be dim.
99' GMC P/U
69' Camaro X-11 350/T350,AC,PS,PB, 12 Bolt
96' 17' CC KEY WEST w/85 Yamaha (has shark fins on the sides like the 69')