Jeep grand cherokee Owner's Manual page 540

538 STARTING AND OPERATING
CAUTION!
If the trailer weighs more than 1,000 lbs (454 kg)
loaded, it should have its own brakes and they
should be of adequate capacity. Failure to do this
could lead to accelerated brake lining wear, higher
brake pedal effort, and longer stopping distances.
• Do not interconnect the hydraulic brake system or
vacuum system of your vehicle with that of the trailer.
This could cause inadequate braking and possible
personal injury.
• An electronically actuated trailer brake controller is
required when towing a trailer with electronically
actuated brakes. When towing a trailer equipped with
a hydraulic surge actuated brake system, an electronic
brake controller is not required.
• Trailer brakes are recommended for trailers over
1,000 lbs (454 kg) and required for trailers in excess of
1,653 lbs (750 kg).
Towing Requirements — Trailer Lights And Wiring
Whenever you pull a trailer, regardless of the trailer size,
stoplights and turn signals on the trailer are required for
motoring safety.
The Trailer Tow Package may include a four- and 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.