Ignition Off Draw (IOD) Tests

High battery current draw, greater than 30 milliamps, with the ignition switch in the OFF position will discharge a battery. After a vehicle has experienced a dead battery and has been serviced the vehicle Ignition Off Draw (IOD) should be checked. To determine if a high current draw condition exists then check the vehicle with a multimeter on the Milliampere Scale.
1. Cycle the ignition switch ON to OFF and remove the ignition key. Ensure that both doors are closed.

Disconnect Battery Negative Cable:

2. Disconnect the battery ground cable.

Ignition Off Draw Test:

3. Using a multimeter with a 10 amp range place the meter in-line between the battery ground terminal and the ground cable.
4. Test current draw, if GREATER THAN 0.6 amps (600 milliamps) after one minute go to Step 1. If less than 0.6 amps (600 milliamps) go to Step 5.
a. Ensure all lamps are OFF.
b. Pull and install each fuse in the PDC one at a time and check for the current draw to drop below 30 milliamps. If no current draw drop go to Step 3. If current draw drops repair circuit as necessary. c. Remove all fuses from the PDC. If no current draw drop occurs. Disconnect the generator B+ wire. If current draw drops, replace the generator. If no current draw drop check wiring and repair as necessary.
5. If current draw, is LESS THAN 0.6 amps (600 milliamps) after one minute:
a. Set multimeter to the milliamp scale and check for a reading less than 30 milliamps. If more than 30 milliamps go to Step 2. If less than 30 milliamps there is not an excess current draw.
b. Pull and install each fuse in the PDC one at a time and check for the current draw to drop below 30 milliamps. If no current draw drop go to Step 3. If current draw drops repair circuit as necessary.

CAUTION: Do not open the vehicle door with the milliamp meter connected

c. Remove all fuses from the PDC. If no current draw drop disconnect the generator B+ wire. If current draw drops replace the generator. If no current draw drop check wiring and repair as necessary.