Lincoln Electric 2004 Town Car Owner's Manual page 217

Roadside Emergencies
3. Once the disabled vehicle has been started, run both engines for an
additional three minutes before disconnecting the jumper cables.
Removing the jumper cables
Remove the jumper cables in the reverse order that they were
connected.
1. Remove the jumper cable from the ground metal surface.
Note: In the illustrations, lightning bolts are used to designate the
assisting (boosting) battery.
2. Remove the jumper cable on the negative (-) connection of the
booster vehicle's battery.
217
2004 Town Car (tow)
Owners Guide (post-2002-fmt)
USA English (fus)