Saturn Parasitic Load Test Device

The parasitic load test device (SA 9130Z) is used with a digital multimeter. The test device is used to measure parasitic current drain from the battery with the ignition and all accessories off. The load tester, constructed with one ohm resistance and a built-in circuit protection device opens when the current exceeds approximately one amp. When the circuit is opened, the user is alerted by a red LED indicator. The parasitic load test device is put into the circuit between the negative battery terminal and the negative battery cable so it effectively becomes a load in series with all other vehicle loads.

IMPORTANT: The alligator clamp on the parasitic load test device must be connected to the flat pad part on the negative battery cable. Do not connect the alligator clamp to the bolt on the negative battery cable, this will cause incorrect readings.

IMPORTANT: The ignition key must be removed from the cylinder before load testing. The key reminder circuit, activated by the key cylinder switch when the key is in the ignition cylinder, adds 20 milliamps of current draw.

IMPORTANT: The fog lamp switch must be in the Off position before load testing. In the On position, the fog lamp switch consumes about 6 milliamps of current draw regardless of the park ignition switch position or whether the key is in the ignition.




1. Turn the ignition and all accessories Off and remove key from ignition switch.
2. Disconnect the cable from the negative battery terminal.
3. Install the parasitic load tester between the negative cable and the negative battery terminal so that the one ohm resistor is in series with the other resistances.

IMPORTANT: The alligator clamp on the parasitic load test device must be connected to the flat pad part on the negative battery cable. Do not connect the alligator clamp to the bolt on the negative battery cable; this will cause incorrect readings.

IMPORTANT: The ignition key must be removed from the cylinder before load testing. The key reminder circuit, activated by the key cylinder switch when the key is in the ignition cylinder, adds 20 milliamps of current draw.




4. Set the multimeter to the MILLIVOLT scale.

5. Measure the current across the tester by putting the multimeter probes on two terminals on the end of the tester. The reading obtained is in volts. This reading is directly converted to milliamps. Should the parasitic current draw exceed one amp, the LED indicator on the test device will light. This may indicate that a vehicle accessory is on. Normal parasitic current drain is between 8.75-9.5 milliamps.
6. To find the source of the excessive load, start removing the fuses and modules in a systematic way. When the voltage drops across the tester, the circuit or circuits protected by that fuse is the source of the current drain. Also remove the fusible link from the generator to check for a voltage drop. If the voltage drop is greater than two volts replace the generator. Repair the circuit and perform the parasitic load test again to verify the repair.