RAM 3500 Truck 4WD V10-8.0L VIN W (1997)
Trailer Connector: Technical Service Bulletins
Electrical - Trailer Tow Wiring Information
NO: 08-33-96
SUBJECT:
Trailer Tow Wiring Information
DATE: Oct. 11, 1996
DISCUSSION:
Chrysler Corporation has offered optional trailer tow packages on all 1994 through 1997 Dodge Ram Trucks and has made trailer tow packages available
through Mopar for vehicles that were not built with the trailer tow package. Several changes to the trailer tow wiring have occurred since the Dodge Ram
Truck was introduced. This bulletin identifies these changes and provides part numbers for the trailer tow wiring harnesses, relays, and flashers. In
addition, this bulletin identifies the part numbers for the Mopar trailer tow packages required to adapt trailer wiring to a vehicle that did not have the
trailer tow package installed as original equipment from the factory.
TRAILER WIRING IDENTIFICATION
The trailer tow wiring 7-terminal connector (located on the receiver hitch), is configured with the following circuits: (Figure 1)
Some of the circuits of the 7-terminal connector may be somewhat difficult to identify.
The following explains those circuits that may be somewhat confusing.
Cavity-2 Trailer Tow Electrical Brake Output
This circuit provides a connection between the trailer tow 7-terminal connector and an electric trailer brake system. An electric trailer brake kit was
introduced at the beginning of the 1996 model year. The kit includes an electric trailer brake jumper with unterminated leads, heavy duty flasher, a
7-terminal to 4-terminal adapter, and an
instruction card. The instruction card identifies that the trailer brake circuit mating connector is located in the instrument panel near the steering column.
This kit is utilized throughout Chrysler Corporation on several different vehicle applications and on the Dodge Ram truck, the mating connector can be
located behind the fuse block near the dash panel, not near the steering column as stated by the instruction card.
Cavity-3 Trailer Tow Relay
The trailer tow relay circuit provides a 30 amp circuit (40 amp for 1996 and 1997) to feed the trailer's tail/park lamp circuit. This circuit is connected to
fuse 7 in the Power Distribution Center (PDC). The relay is also located inside the PDC. The relay is energized anytime the park lamp switch is turned
ON. The park lamp switch provides the necessary current to operate the trailer tow relay coil.
WARNING:
IT IS IMPERATIVE THAT THE TRAILER TOW RELAY BE UTILIZED WHEN OPERATING THE TAIL/PARK LAMPS ON THE TRAILER.
THE CURRENT CARRYING CAPACITY OF THE HEADLAMP SWITCH IS LIMITED TO THE LAMPS UTILIZED BY THE VEHICLE
ONLY.
Cavity-4 Fused B+
This circuit provides a 30 amp (40 amp for 1996 and 1997) circuit for operating electrical circuits on the trailer. This circuit is connected to fuse 7 in the
PDC. This circuit does not contain any isolation device between the 7-terminal connector and the fuse. Current will not be interrupted to this circuit with
the ignition switch in the OFF position.
