FORD 2002 E-450 v.1 - Manual (Page 224)

Connect:
1. Reconnect the auxiliary battery
frame ground.
2. Reconnect the primary battery
ground cable.
Diesel engines
Disconnect:
Secondary positive cable remains energized after disconnection.
Make sure the tool does not contact any ground surface.
1. Disconnect the secondary positive
cable from the primary battery
terminal.
Maintenance and specifications
224