Test D: Power Door Locks Operate Only With Engine Running

Check Battery Voltage - Turn ignition off. Using a voltmeter, check voltage between battery terminals. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, check and repair charging system as necessary.
Check For Binding Or Sticking Door Lock - Manually lock and unlock door lock and check for binding or sticking lock. If door lock is not binding or sticking, go to next step. If door lock is binding or sticking, repair or replace as necessary and retest system operation.
Check Connector & Terminals - Remove door lock switches. Check connectors for loose, corroded or damaged terminals. Repair or replace as necessary and retest system operation. If connector and terminals are okay, no problem is indicated at this time.