I am curious why in Subaru's procedure for determining parasitic current, they instruct us to use a bypass wire and leave it in place for 5 minutes before taking a current measurement. Why can't we just leave the ammeter hooked up for 5 minutes before taking the measurement?
Subaru's procedure:
Items required for test:
^ Pen and paper for recording radio and satellite radio pre-sets
^ Digital Volt Ohm Meter
^ 10 MM wrench
^ 16 gauge by-pass wire, about 12 inches long, w/ proper securing attachments at each end
Test Procedure:
1) Remove battery negative cable
2) Connect one end of by-pass wire to the battery's negative post then connect the other end to negative battery cable end Simply wrapping then twisting the stripped back ends of the by-pass wire around the post and terminal will be sufficient Reinstall the negative cable on the battery post
3) Wait 5 minutes before proceeding to the next step. This will allow the system voltage to stabilize. During this time, be sure the glove box door, trunk, tailgate, and all vehicle doors are closed and their corresponding lamps are off. Also, be sure that the head lamps, fog lamps, and all switches are off. The ignition key needs to be removed, and the doors must be locked (make sure not to lock the keys in the car). Remove the negative battery cable, making sure the by-pass wire has not lost contact. If contact is lost, you will need to start at step # 2 again.
4) Make sure your voltmeter is set to milliamp (mA) setting. Connect the test leads of your voltmeter to the negative battery cable and the negative battery post. Remove the by-pass wire you installed in steps # 2 and # 3 and measure the current draw.
After the 5 minute stabilization period, the measured draw should be a maximum of 150 milli-amps. This maximum draw value is read with the key out of the ignition switch.
If your results are greater than the above specification, further diagnosis will be necessary to determine the source of the excessive current draw. This should be done using normal electrical circuit testing until the source of this excessive draw is determined and repaired.
After confirming the repair, the customer's radio presets and clock time should be reset properly.
Subaru's procedure:
Items required for test:
^ Pen and paper for recording radio and satellite radio pre-sets
^ Digital Volt Ohm Meter
^ 10 MM wrench
^ 16 gauge by-pass wire, about 12 inches long, w/ proper securing attachments at each end
Test Procedure:
1) Remove battery negative cable
2) Connect one end of by-pass wire to the battery's negative post then connect the other end to negative battery cable end Simply wrapping then twisting the stripped back ends of the by-pass wire around the post and terminal will be sufficient Reinstall the negative cable on the battery post
3) Wait 5 minutes before proceeding to the next step. This will allow the system voltage to stabilize. During this time, be sure the glove box door, trunk, tailgate, and all vehicle doors are closed and their corresponding lamps are off. Also, be sure that the head lamps, fog lamps, and all switches are off. The ignition key needs to be removed, and the doors must be locked (make sure not to lock the keys in the car). Remove the negative battery cable, making sure the by-pass wire has not lost contact. If contact is lost, you will need to start at step # 2 again.
4) Make sure your voltmeter is set to milliamp (mA) setting. Connect the test leads of your voltmeter to the negative battery cable and the negative battery post. Remove the by-pass wire you installed in steps # 2 and # 3 and measure the current draw.
After the 5 minute stabilization period, the measured draw should be a maximum of 150 milli-amps. This maximum draw value is read with the key out of the ignition switch.
If your results are greater than the above specification, further diagnosis will be necessary to determine the source of the excessive current draw. This should be done using normal electrical circuit testing until the source of this excessive draw is determined and repaired.
After confirming the repair, the customer's radio presets and clock time should be reset properly.
