Chrysler 2008 PT Cruiser - Manual (Page 355)

Towing Requirements — Trailer Lights & Wiring
Whenever you pull a trailer, regardless of the trailer size,
stop lights and turn signals on the trailer are required for
motoring safety.
The Trailer Tow Package may include a four- or seven-
pin wiring harness. Use a factory approved trailer har-
ness 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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