Chrysler Dodge Caravan 2002 Manual page 2276

RS
BLOWER MOTOR RELAY (Continued)
The blower motor relay terminals are connected to
the vehicle electrical system through a receptacle in
the Intelligent Power Module (IPM). The inputs and
outputs of the compressor clutch relay include:
• The common feed terminal (30) receives a bat-
tery current input from the battery through a B(+)
circuit at all times.
• The coil ground terminal (85) receives a ground
input through the front/rear blower motor relay con-
trol circuit only when the FCM electronically pulls
the control circuit to ground.
• The coil battery terminal (86) receives a battery
current input from the battery through a B(+) circuit
at all times.
• The normally open terminal (87) provides a bat-
tery current output to the blower motor resistor
(manual heater-A/C control) or blower power module
(automatic heater-A/C control) through a fuse in the
IPM on the fused rear blower motor relay output cir-
cuit only when the blower motor relay coil is ener-
gized.
• The normally closed terminal (87A) is not con-
nected to any circuit in this application, but provides
a battery current output only when the blower motor
relay coil is de-energized.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices, and grounds.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RELAY
The rear blower motor relay (Fig. 6) is located in
the Intelligent Power Module (IPM), which is in the
engine compartment near the battery. See the fuse
and relay layout map molded into the inner surface
of the IPM cover for rear blower motor relay identi-
fication and location. Remove the relay from the IPM
to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75 ± 5 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, use a DRBIII
further diagnosis of the relay circuits. Refer to the
appropriate diagnostic
replace the faulty relay.
scan tool to perform
information. If not
Fig. 6 Blower Motor Relay
NUMBER
30
85
86
87
87A
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unlatch and remove the cover from the Intelli-
gent Power Module (IPM) (Fig. 7).
Fig. 7 Intelligent Power Module
1 - BATTERY THERMAL GUARD
OK,
2 - INTELLIGENT POWER MODULE
3 - FRONT CONTROL MODULE
CONTROLS - REAR
IDENTIFICATION
COMMON FEED
COIL GROUND
COIL GROUND
NORMALLY OPEN
NORMALLY CLOSED
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