Parasitic Load Testing

Tools Required:
J 38758 Current Draw Test Switch
Ammeter with at least 10 amp measurement capacities

1. Remove battery cable from negative battery terminal.
2. Install current drain test tool, male end, to negative battery terminal.
3. Turn current drain test tool to the "open" position.
4. Install negative battery cable to female end of current drain tool.
5. Turn drain test tool to the "closed" position.
6. Road test vehicle while activating all accessories (radio, A/C, etc).
7. Turn ignition switch to the "locked" position and remove ignition key.
8. Set ammeter to the 10 amp scale and connect to terminals on current drain test tool.
9. Turn current drain test tool to the "open position to allow current to flow though the ammeter.
10. Wait at least 60 seconds. Proceed checking current reading. If current reading is at or below 2 amps, close the current drain test tool (to maintain continuity in the electrical system) and switch down to the 2 amp scale for a more accurate reading when drain test tool is reopened.
11. Proceed as follows:

NOTE: ALWAYS close the current drain test tool before removing a fuse to maintain continuity in the electrical system and to avoid damaging the ammeter due to accidental overloading (i.e., opening door to change fuse, etc).
A. Current draw less than 25 milliamps is acceptable. Check charging system for proper operation.
B. Current draw over 25 milliamps; remove PCM fuse.

PCM Draw Test:

- If ammeter drops more than 10 milliamps, refer to "PCM Draw Test".
- If ammeter shows less than 10 milliamps drop, remove circuit/system fuses one at a time until the current draw returns to a value less than 25 milliamps. This will indicate the circuit/system causing the draw.

Important: Repeat parasitic current drain procedure after any repair has been completed.

12. When cause of excessive current draw has been located and repaired, remove current drain test tool and reconnect negative battery cable. Reset clock, radio, etc.