Ignition-Off Draw Test

Testing for HIGHER AMPERAGE IOD must be performed first to prevent damage to most milliamp meters.

A standard 12 volt test light and a milliamp meter that is equipped with two leads will be used for the following tests. The milliamp meter should be able to handle up to two amps.

1. Verify that all electrical accessories are OFF. Turn off all lights, close all doors and remove ignition key.
2. Disconnect battery negative cable.

IOD Test:

3. Connect a 12 volt test light between the negative cable terminal and the battery negative side terminal. The test light may be brightly lit for up to three minutes or may not be lit at all. This depends on the electronic components on the vehicle.
a. The term brightly used throughout the following tests. This implies the brightness of the test light will be the same as if it were connected across the battery terminals. This would be with a fully charged battery.
b. The test light or the milliamp meter MUST be positively connected to the negative side terminal and the battery negative cable during all IOD testing.
c. Do not allow the test light or the milliamp meter to become disconnected during any of the IOD tests. If this happens, the electronic timer functions will be started and all IOD tests must be repeated from the beginning. Clamp the test light at both ends to prevent accidental disconnection.
d. After connecting test light, cycle the theft alarm transmitter to disarm the Alarm System. The horn should stop sounding and the park and tail lamps stop flashing. If the transmitter is NOT cycled, this vehicle will have temporary high IOD of 15 amps or more for up to 65 minutes. This higher IOD can often mask another problem and should be considered when performing IOD testing.
e. After three minutes time has elapsed, the test light should turn OFF or be dimly lit depending on the electronic components on the vehicle. If the test light remains BRIGHTLY lit, do not disconnect test light. Disconnect each fuse or circuit breaker until test light is either OFF or DIMLY lit. This will eliminate higher amperage IOD. It is now safe to install the milliamp meter without damage to the meter to check for low amperage IOD.
f. If test light is still brightly lit after disconnecting each fuse and circuit breaker; disconnect the wiring harness from the generator. Refer to Generator. Do not disconnect test light.

CAUTION: This last test has higher amperage IOD and must be performed before going on with low amperage IOD tests. The higher amperage IOD must be eliminated before hooking up milliamp meter to check for low amperage IOD. If higher amperage IOD has not been eliminated, milliamp meter may be damaged. Most milliamp meters will not handle over one or two amps. Do not hook up meter if test light is glowing brightly Refer to maximum amperage specifications and instructions supplied with milliamp meter.

After higher amperage IOD has been corrected, low amperage IOD may be checked. The MAXIMUM IOD 30 MILLIAMPERES.

Low Amperage IOD Test:

4. With test light still connected, connect milliamp meter between battery negative side terminal and battery negative cable. Do not open any doors or turn on any electrical accessories with the test light disconnected and the milliamp meter connected. Meter may be damaged.
5. Disconnect test light. Milliamp meter reading should be less than 30 milliamperes. If low amperage IOD is not within specifications:
a. Disconnect the Powertrain Control Module (PCM) and the Ignition Control Module (ICM). The PCM and ICM are located under the hood on the left side of dash panel. Refer to Ignition for more information.
b. The circuit to the radio.
c. The wiring harness from the generator. Refer to Generator.
- Check each component until excessive IOD is found.
- Each time the test light or milliamp meter is disconnected and connected, all electronic timer functions will be activated. Tests must be repeated from the beginning.
- Test light or meter MUST remain connected for all tests.