Battery Drain Test

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2003 Ford RV Cutaway, 2003 Ford Econoline, 2003 Ford E550 Super Duty, 2003 Ford E450 Super Duty, and 2003 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

Ensure junction box/fuse panels are accessible without turning on interior and hood lights. Drive vehicle over 30 MPH for at least 5 minutes. Park vehicle and allow to sit with ignition off for at least one hour to allow electronic modules to power down. Go to next step.
Connect a fused jumper wire between positive battery cable on right side battery and positive battery post. Disconnect positive battery cable from positive battery post, without breaking the jumper wire connection to prevent modules from resetting. Go to next step.
NOTE: It is very important that continuity is not broken between positive battery post and positive battery cable when disconnecting battery cable or connecting ammeter. If continuity is broken, go to step 1.
Ensure ammeter is set to read milliamps with at least a 10-amp capability. Connect ammeter between positive battery cable and positive battery post. Remove fused jumper wire. Go to next step.
If excessive current draw is present (50 mA or more), pull fuses from battery/central junction box one at a time and note any current drop when each fuse is removed. DO NOT reinstall fuses until test is complete. Go to next step.
Check wiring diagrams for any circuits that run from battery without passing through battery/central junction box. Disconnect these circuits if current draw still exists. Repair appropriate circuits as necessary. See POWER DISTRIBUTION in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.