PINPOINT TEST G: NO OPERATION IN HIGH BLOWER SETTING
Is the resistance less than 5 ohms?
Yes
REPLACE the A/C blower motor resistor. RETEST the system for normal operation.
No
REPAIR Circuit 261 (O/BK). TEST the system for normal operation.
F5
CHECK THE BLOWER MOTOR SWITCH
Turn the function selector switch to the FLOOR position and slowly rotate the blower motor switch from the LO
position to the HI position and back several times.
Does the A/C blower motor operate in all switch positions without interruption?
Yes
CHECK the system operations in all function selector switch positions and A/C blower motor speeds. If OK,
ADVISE the customer on correct operation of the system.
No
GO to
F6
.
F6
CHECK THE BLOWER MOTOR SWITCH RESISTANCE
Blower Motor Switch
Measure the resistance between the blower motor switch terminals in each switch position.
Switch Position Continuity Between Terminals
LO
None
Low medium
2 and 3
High medium
2, 3 and 4
HI
1, 2 and 4
Is the resistance between the specified terminals less than 5 ohms?
Yes
CHECK for opens and shorts; REPAIR as required Circuits 752 (Y/R) or 754 (LG/W). RETEST the system for
normal operation.
No
REPLACE the blower motor switch. TEST the system for normal operation.
CONDITIONS
DETAILS/RESULTS/ACTIONS
G1
CHECK THE A/C BLOWER MOTOR OPERATION
Turn the function selector switch to the FLOOR position and the blower motor switch to the position next to the HI
position.
Does the A/C blower motor operate?
Yes
GO to
G2
.
No
Page 27 of 30
1999 F-150/250 Workshop Manual
8/16/2010
http://www.fordtechservice.dealerconnection.com/pubs/con...
