Electrical Leaks Reprinted from CASCO newsletter, September 2013
Electrical leaks are an unwanted current flow and can occur due to worn or damage insulation, corroded connections or excessive dampness. This is nothing more annoying than jumping into your Thunderbird in full anticipation of an enjoyable drive and finding the battery too low to start the car. If you think you have an electrical leak (or short) that is running down your battery, here’s how to find it:
1. Turn off everything that uses electricity. 2. Remove the battery cable that goes to the starter solenoid from the battery. 3. Connect a multimeter set to measure DC volts between the battery terminal and the cable. If it reads battery voltage, there is leakage or a short. 4. Switch your meter to read DC amps (start on the highest range to prevent damage to the meter) and measure the current flow. If the reading is 1 amp or more, then quite likely there is something still turned on. Any current flow between 1 amp and .01 amps is a major electrical leak. Less than .01 amps is a minor leak. 5. If a leak is detected, first clean the battery terminals, battery top, and battery cables, then one a time remove fuses and disconnect wires until the current drops to zero. When it does, you’ve found the source of the leak.