Pinpoint Test M: The Blower Motor Is Inoperative
Refer to Wiring Diagrams Cell
55
, Automatic Climate Control System for schematic and connector information.
Normal Operation
Under normal operation, the blower motor relay coil receives voltage through circuit 181 (BN/OG). The coil receives ground from the electronic automatic temperature control (EATC)
module through circuit 364 (BK/LG) if any position but OFF is selected. Voltage is supplied to the relay switch contact through circuit 181 (BN/OG). When the relay coil is energized, voltage
Test Step
Result / Action to Take
L1 CHECK THE A/C PRESSURE PCM PID
Ignition ON.
Enter the following diagnostic mode on the scan tool: A/C Pressure PCM PID.
With the manifold gauge set connected, compare the pressure readings of the
manifold gauge set and the A/C pressure PID.
Are the pressure values of the manifold gauge set and the A/C pressure PID
similar?
Yes
GO to
L2
.
No
INSTALL a new A/C pressure transducer. TEST the system for normal operation.
L2 CHECK A/C REQUEST PCM PID (ACCS) WITH THE A/C OFF
Enter the following diagnostic mode on the scan tool: A/C REQUEST PCM PID.
Press the OFF manual override button on the EATC module.
Does the A/C REQUEST PCM PID read OFF?
Yes
GO to
L4
.
No
GO to
L3
.
L3 CHECK A/C SWITCH EATC PID WITH THE A/C OFF
Enter the following diagnostic mode on the scan tool: A/C SWITCH EATC PID.
Press the OFF manual override button on the EATC module.
Does the A/C SWITCH EATC PID read OFF?
Yes
GO to
L6
.
No
GO to
L7
.
L4 CHECK FOR VOLTAGE TO THE A/C COMPRESSOR CLUTCH FIELD COIL
Ignition OFF.
Disconnect: A/C Compressor Clutch Field Coil C100.
Ignition ON.
Measure the voltage between A/C compressor clutch field coil C100-1, circuit 321
(GY/WH) and ground.
Is the voltage greater than 10 volts?
Yes
GO to
L5
.
No
ADJUST the A/C compressor clutch gap. REFER to
Air Conditioning (A/C) Clutch Air
Gap Adjustment
in this section. TEST the system for normal operation.
L5 CHECK CIRCUIT 321 (GY/WH) FOR A SHORT TO VOLTAGE
Ignition OFF.
Disconnect: A/C Clutch Relay.
Ignition ON.
Measure the voltage between A/C compressor clutch field coil C100-1, circuit 321
(GY/WH) and ground.
Is the voltage greater than 10 volts?
Yes
REPAIR circuit 321 (GY/WH) for a short to voltage. TEST the system for normal
operation.
No
INSTALL a new A/C clutch relay. CHECK the A/C clutch diode. TEST the system for
normal operation. INSTALL a new diode if necessary.
L6 CHECK THE EATC MODULE CONNECTION
Inspect the module connectors for:
corrosion.
pushed-out terminals.
damaged terminals.
Connect and correctly seat all the EATC module connectors.
Clear the DTCs.
Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new EATC module. REFER to
Section 412-01
. TEST the system for normal
operation.
No
The system is operating correctly at this time. The concern may have been caused by a
loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the
system for normal operation.
L7 CHECK THE PCM CONNECTION
Disconnect all the PCM connectors.
Inspect the module connectors for:
corrosion.
pushed-out terminals.
damaged terminals.
Connect and correctly seat all the PCM connectors.
Clear the DTCs.
Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new PCM. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a
loose or corroded connector.
Page 35 of 45
2006 Town Car Workshop Manual
12/30/2011
http://www.fordtechservice.dealerconnection.com/pubs/content/~WS6G/~MUS~LEN/19/...
