Topaz AWD L4-140 2.3L HSO (VIN S) (1988)
Control Module HVAC: All Technical Service Bulletins
A/C Fan Controller - New Diagnostic Procedure
AIR CONDITIONING - FAN CONTROLLER - DIAGNOSTIC
PROCEDURE
Article No. 89-20-3
FORD:
1987-90 ESCORT 1988-90 TEMPO
LINCOLN-MERCURY: 1988-90 TOPAZ
ISSUE:
Replacing the A/C fan controller may not correct cooling fan or other air conditioning electrical system malfunctions.
ACTION:
If an inoperative A/C cooling fan is found, use the following fan controller and A/C electrical system diagnostic chart and the
appropriate Electrical And Vacuum Troubleshooting Manual (EVTM) to resolve the concern before replacing the A/C fan controller.
NOTE:
THE REPLACEMENT PARTS HAVE INTERNAL CIRCUIT PROTECTION. WHEN THE NEW CONTROLLERS ARE USED TO
SERVICE THESE VEHICLES, TERMINALS # 2 AND # 4 ARE NOT USED. THESE TWO TERMINALS ARE USED ONLY FOR
CONTROLLERS PRIOR TO THE 1987 ESCORT AND THE 1988 TEMPO/TOPAZ.
The following points should be kept in mind when checking the A/C circuits.
1.
Voltage must be available at fan controller pin # 3 for A/C operation.
2.
The A/C clutch coil current must not exceed 6 amps.
3.
If voltage or ground is not available at the controller, use a jumper wire to supply the proper voltage or ground to check fault or proper operation
of the cooling fan A/C system.
4.
Check for voltage at the controller with:
a.
The connector plugged into the controller.
b.
The key in the "RUN" position, except where an exception is noted.
5.
If there is intermittent A/C operation, check for the following items at the cooling fan, coolant switch splices and connector/terminals:
^
Breaks
^
Poor crimps
^
Loose terminals
If the A/C fan controller must be replaced, refer to the appropriate Car Shop Manual, Section 36-20 for service details.