Battery Electrical Drain/ Parasitic Load Test

download
1. Disconnect the battery negative cable. 2. Install the male end of the J 38758 to the negative battery terminal. 3. Turn OFF the test switch. 4. Install the negative battery cable to the female end of the test switch. 5. Install the Scan Tool (or equivalent) or wait for 20 minutes. 6. Turn ON the test switch. 7. Road test the vehicle while activating all accessories, including the radio and the air conditioning. 8. Lower the door glass, then exit the vehicle. Do not move the door handle after closing the door. 9. Open the hood. Important The power down timer will reset to 20 minutes if any wake up inputs are received by a Class 2 device (after the scan tool has put all Class 2 devices to sleep). 10. Put all of the Class 2 devices into the sleep mode. 11. Turn OFF the ignition switch. Remove the key. Important From this point on, electrical continuity must be maintained in the ground circuit of the battery through the Test Switch J 38758 in the ON position or through the ammeter J 39200 . 12. Components such as PCM, VCM, Automatic Air Conditioning, and the Truck Body Control Module have timers that draw several amps of current while they cycle down. This can give a false parasitic drain reading. Wait 20 minutes for these components to power down before continuing this test (or use the scan tool to put all Class 2 devices to sleep). 13. Connect a jumper wire with a 10 A fuse J 36169-A to the terminals of the test switch. 14. Turn the test switch to the OFF position. 15. Wait ten seconds. If the fuse does not blow, the current is less than 10 A. The ammeter can be used safely. 16. Before the fused jumper wire is removed, turn the test switch to the ON position. Important