Ford 2003 Mustang Workshop Manual page 3074

C294c-3, circuit 348 (PK), harness side and ground.
Is there voltage present?
D5 CHECK FOR A SHORTED CLUTCH INPUT
Key in OFF position.
Disconnect: A/C Clutch C100.
Key in ON position.
Measure for voltage at the A/C clutch C100, circuit 347
(BK/YE), harness side and ground.
Is there voltage present?
PINPOINT TEST E: INSUFFICIENT A/C COOLING
E1 CHECK THE CENTER A/C REGISTER DISCHARGE
TEMPERATURE
Carry out the refrigerant system tests. Refer to
Refrigerant System Tests
Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for center A/C register discharge
temperature.
Is the intersection of the two lines within the upper
and lower limits?
Test Step
in this section.
No
INSTALL a new function
selector switch. REFER to
Section 412-04 . TEST the
system for normal operation.
Yes
INSTALL a new constant
control relay module. TEST the
system for normal operation.
No
CHECK the clutch air gap.
REFER to Air Conditioning
(A/C) Clutch Air Gap
Adjustment .
Result / Action to Take
Yes
The tests indicate that the
system is functioning normally.
No
GO to E2 .