Battery - Parasitic Load Test
File In Section: 6 - EngineBulletin No.: 73-64-03
Date: January, 1997
SERVICE MANUAL UPDATE
Subject:
Section 6D1 - Revised Parasitic Load Test
Models:
1996-97 Buick Skylark
1996 Chevrolet Beretta, Corsica
1996-97 Chevrolet Cavalier
1997 Chevrolet Malibu
1996-97 Oldsmobile Achieva
1997 Oldsmobile Cutlass
1996-97 Pontiac Grand Am, Sunfire
This bulletin is being issued to revise the Parasitic Load Test in Section 6D1 of the Service Manual.
Parasitic Load Test
Tools Required:
J 38758 Current Draw Test Switch Ammeter with at least 10 amp measurement capabilities
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 OFF 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 through the ammeter.
Important:
The Interior Lamp circuit is controlled by the Multi-Function Alarm module on the J, L, and N platforms and by the Body Function Controller on the L/N (Chevrolet Malibu, Oldsmobile Cutlass) platform. The module or controller has two modes of operation which determine how long the module or controller will stay "awake" (powered up). When the Multi-Function Alarm module is "awake", it will draw 60 to 80 milliamps.
When the Multi-Function Alarm module is "asleep" (powered down), it will draw 3 to 15 milliamps. When the Body Function Controller is "awake", it will draw approximately 100 milliamps. When the Body Function Controller is "asleep", it will draw 3 to 5 milliamps. Refer to Interior Lights in Electrical Diagnosis in the Service Manual for information on the modes of operation for the Multi-Function Alarm module or Body Function Controller.
10. Wait at least 20 minutes to ensure that the Multi-Function Alarm module or Body Function Controller is "asleep". Proceed checking current reading. If current reading is at or below two amps, close the current drain test tool (to maintain continuity in the electrical system) and switch down to the two amp scale for a more accurate reading.
11. With the drain test tool open, proceed as follows:
a. If current draw is less than 22.5 milliamps with the Multi-Function Alarm module or Body Function Controller "asleep", check the charging system for proper operation. Refer to Electrical Diagnosis, Cell 30, in the Service Manual.
Notice:
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.).
b. If current draw is over 22.5 milliamps with the Multi-Function Alarm module or Body Function Controller "asleep", remove the PCM fuse and note ammeter reading.
^ If ammeter drops more than 10 milliamps, refer to Figure 7, PCM Draw Test, in the applicable Service Manual.
^ If ammeter shows less than 10 milliamps drop, remove circuit/system fuses one at a time until the current draw is less than 22.5 milliamps with the Multi-Function Alarm module or Body Function Controller "asleep". Refer to Electrical Diagnosis in the Service Manual for circuit/system information.
Important:
Repeat parasitic load test 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.