2003 FORD MUSTANG Workshop Manual

Page 3057 of 4378

FORD MUSTANG 2003  Workshop Manual PINPOINT TEST A: INCORRECT/ERRATIC DIRECTION OF AIRFLOW 
FROM OUTLET  �z
Is there voltage present?  Test Step  Result / Action to 
Take  A1 CHECK AIRFLOW FROM DEFROSTER OUTLETS 
�z
Key in START positi

Page 3058 of 4378

FORD MUSTANG 2003  Workshop Manual �z
Disconnect: Vacuum Supply Hose. 
�z Connect one end of the vacuum supply hose to a vacuum pump 
and test for leaks. 
�z Does the hose leak?  Yes 
REPAIR or INSTALL a 
new vacuum hose. 
TEST the sys

Page 3059 of 4378

FORD MUSTANG 2003  Workshop Manual �z
Pump 51 kPa (15 in- Hg) vacuum on the A/C vacuum check valve 
and observe the gauge reading. 
�z If the vacuum loss exceeds 3.37 kPa (1 in- Hg) per minute, 
remove the A/C vacuum check valve from t

Page 3060 of 4378

FORD MUSTANG 2003  Workshop Manual �z
At each function selector switch position, apply 51 kPa (15 in- Hg) 
of vacuum and check for vacuum drop. 
�z Does the vacuum drop exceed 3.37 kPa (1 in- Hg) per 
minute?  No 
RECONNECT the in-
lin

Page 3061 of 4378

FORD MUSTANG 2003  Workshop Manual �z
Does the vacuum drop?  system for normal 
operation. 
No 
REPAIR or INSTALL a 
new function selector 
switch. TEST the 
system for normal 
operation. 
A13 REVIEW THE VEHICLES HISTORY 
�z
Key in OF

Page 3062 of 4378

FORD MUSTANG 2003  Workshop Manual �z
Is the hose pinched or kinked?  A17 CHECK VACUUM CIRCUIT CONNECTIONS 
�z
Check each vacuum hose connection to determine if it is partially 
connected or disconnected. 
�z Is a vacuum hose disconnec

Page 3063 of 4378

FORD MUSTANG 2003  Workshop Manual PINPOINT TEST B: INSUFFICIENT, ERRATIC, OR NO HEAT  �z
Does the vacuum control motor hold a vacuum?  A20 CHECK THE VACUUM CONTROL MOTOR INSTALLATION 
�z
Key in OFF position. 
�z Check the attachment o

Page 3064 of 4378

FORD MUSTANG 2003  Workshop Manual PINPOINT TEST C: THE A/C DOES NOT OPERATE/DOES NOT 
OPERATE CORRECTLY  �z
Is the heater core inlet hose too hot to handle?  B3 CHECK THE ENGINE COOLING SYSTEM INCLUDING 
RADIATOR CAP FOR LEAKS  �z
Fil