Chrysler 2008 Pacifica - Manual (Page 346)

The Trailer Tow Package may include a 4 and 7 pin
wiring harness. Use a factory approved trailer harness
and connector.
NOTE: Do not cut or splice wiring into the vehicles
wiring harness.
The electrical connections are all complete to the vehicle
but you must mate the harness to a trailer connector.
Refer to the following illustrations.
4 - Pin Connector
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