Chrysler Concorde 2004 Service Manual page 1579

LH
RADIATOR FAN RELAY (Continued)
Fig. 24 Radiator Fan Relays (HI/LO & HI)
1 - COOLANT RECOVERY PRESSURE CONTAINER
2 - RADIATOR FAN HI/LO RELAY
3 - RADIATOR FAN HI RELAY
All vehicles (except 2.7L base) are also equipped
with No. 1 and No. 2 radiator fan relays that are
mounted to the radiator fan motor shroud (Fig. 25).
Fig. 25 Radiator Fan Relays - No. 1 & No. 2 (Except
2.7L Base)
1 - ELECTRICAL CONNECTOR
2 - RADIATOR FAN MOTOR NO. 2
3 - RADIATOR FAN RELAY NO. 2
4 - RADIATOR FAN RELAY NO. 1
5 - RADIATOR FAN MOTOR NO. 1
OPERATION
2.7L BASE
The cooling system uses two fans. Both fans oper-
ate at two different speeds, low and high. Depending
on engine coolant temperature and A/C system high
side pressure, the fans operate at either low or high
speed. The PCM controls radiator fan speed by
grounding the coil side of either the HI/LO fan relay
or the HI fan relay. The ignition switch supplies volt-
age to the coil sides of the relay. When the PCM
grounds the coil side of the relay, the contacts close
and the battery supplies power to the fans. Refer to
WIRING DIAGRAMS.
EXCEPT 2.7L BASE
The cooling system uses two fans. Both fans oper-
ate at two different speeds, low and high. Depending
on engine coolant temperature and A/C system high
side pressure, the fans operate at either low or high
speed. The PCM controls radiator fan speed by
grounding the coil side of either the HI/LO fan relay
or the HI fan relay. Low speed radiator fan function
is achieved by running both fan motors in a series
circuit. High speed radiator fan function is achieved
by running both fan motors in a parallel circuit.
Refer to WIRING DIAGRAMS.
WATER PUMP
DIAGNOSIS AND TESTING - WATER PUMP
A quick test to determine water pump operation is
to check for proper heater system performance (Refer
to 24 - HEATING & AIR CONDITIONING - DIAG-
NOSIS AND TESTING). A defective pump will not
circulate heated coolant through the heater hoses.
For additional diagnosis, (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING). For water pump
inspection, (Refer to 7 - COOLING/ENGINE/WATER
PUMP - INSPECTION).
WATER PUMP - 2.7L
DESCRIPTION
The 2.7L pump has a die cast aluminum housing
and a plastic swept vane impeller. It bolts directly to
the cylinder block, behind the timing chain cover
(Fig. 26). The water pump is driven by the back side
of the engine primary timing chain.
REMOVAL
The water pump on all models can be replaced
without discharging the air conditioning system.
ENGINE 7 - 33