Jeep 1996 Grand Cherokee Service Manual page 720

ZJ
GENERAL INFORMATION
INTRODUCTION
Two trailer tow packages are available; a factory
installed package and a package with after-market
provisions. This section provides separate wiring dia-
grams for each.
DESCRIPTION AND OPERATION
TRAILER TOW—FACTORY INSTALLED
The factory installed trailer tow system in this
vehicle uses three relays and a circuit breaker along
with the trailer tow wiring connector.
Circuit A250 from fuse 11 in the Power Distribu-
tion Center (PDC) powers circuit F70 through fuse 8
in the junction block. Circuit F70 supplies battery
voltage for the trailer tow circuit breaker and the
contact side of the stop lamp relay
The trailer tow circuit breaker is taped to the
trailer tow harness located in the left rear quarter
panel.
STOP LAMP RELAY
Power for the coil side of the stop lamp relay is
supplied by circuit L50. This circuit connects to the
stop lamps. Ground for the coil side is supplied on
circuit Z1.
When the operator presses the brake pedal, voltage
flows through the coil of the relay to ground causing
the contacts in the relay to connect circuits F70 and
95.
Circuit 95 connects to the left and right turn signal
relays. Voltage flows through the closed contacts in
the relays to the trailer tow connector.
RIGHT TURN RELAY
Power for the coil side of the right turn relay is
supplied by circuit L60. This circuit connects to the
right side turn signal lamps. Ground for the coil side
of the relay is supplied on circuit Z1.
When the operator turns the right turn signal ON,
power flows through the coil in the relay to ground
causing the contacts in the relay to switch from the
normally CLOSED position to connect circuits 94 and
L60.
Circuit 94 is the feed for the contact side of the
relay. Circuit L60 connects from the relay to the
trailer tow connector.
8W - 54 TRAILER TOW
1996 Grand Cherokee
Publication No. 81-370-6147
TSB 26-02-96 February, 1996
8W-54 TRAILER TOW
Circuit 94 is fed power through the normally
CLOSED side of the stop lamp relay by circuit F70.
Circuit F70 is HOT at all times and protected by a
circuit breaker located in the right rear quarter
panel.
LEFT TURN RELAY
Power for the coil side of the left turn relay is sup-
plied by circuit L61. This circuit connects to the left
side turn signal lamps. Ground for the coil side of the
relay is supplied on circuit Z1.
When the operator turns the left turn signal ON,
power flows through the coil in the relay to ground
causing the contacts in the relay to switch from the
normally CLOSED position to connect circuits 94 and
L61.
Circuit 94 is the feed for the contact side of the
relay. Circuit L61 connects from the relay to the
trailer tow connector.
Circuit 94 is fed power through the normally
CLOSED side of the stop lamp relay by circuit F70.
Circuit F70 is HOT at all times and protected by a
circuit breaker located in the right rear quarter
panel.
HELPFUL INFORMATION
• Check fuse 11 in the PDC
• Check fuse 8 in the junction block
• Check the In-Line circuit breaker
• A trailer brake provision is taped to the harness
at the lower left of the instrument panel
TRAILER TOW—AFTER-MARKET
The after-market trailer tow connector is located in
the left rear quarter panel. The connector contains
feed circuit F70 from fuse 8 in the junction block.
Circuit L60 from the right turn signals, circuit L90
for parking lamps, and circuit L50 from the stop
lamp switch.
SCHEMATICS AND DIAGRAMS
WIRING DIAGRAM INDEX
The following index covers all components found in
this section of the wiring diagrams. If the component
you are looking for is not found here, refer to section
8W-02 for a complete list of all components shown in
the wiring diagrams.
8W - 54 - 1