A/C Fan Controller/Electrical System Diagnostics (89-20-3)
Publication date: 1970-01-01Reference number: 89-20-3
A/C FAN CONTROLLER/ELECTRICAL SYSTEM DIAGNOSTICS
TECHNICAL SERVICE BULLETIN
Reference Number(s): 89-20-3
APPLICATION
1987-90 Ford Escort, 1988-90 Ford Tempo; 1988-90 Lincoln-Mercury Topaz
SUBJECT
Air Conditioning Fan Controller Diagnostic Procedure.
REFERENCE
Ford Technical Service Bulletin No. 89-20-3
CONDITION & CAUSE
Incorrect cooling or other air conditioning electrical system malfunctions may not be alleviated by replacing the A/C fan controller.
DIAGNOSIS PROCEDURE
Use the following fan controller and A/C electrical system diagnostic chart and the appropriate Electrical and Vacuum Troubleshooting Manual (EVTM) to resolve an inoperative A/C cooling fan 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.
Keep the following points in mind when checking the A/C circuits:
- For A/C operation, voltage must be available at fan controller pin #3.
- The A/C clutch coil current must not exceed 6 amps.
- Use a jumper wire to supply the proper voltage or ground to check fault or proper operation of the cooling fan A/C system if voltage or ground is not available at the controller.
- Check for voltage at the controller with:
- the connector plugged into the controller.
- the key in the "RUN" position, except where an exception is noted.
- Check for the following items at the cooling fan, coolant switch splices and connector/terminals if there is intermittent A/C operation:
- breaks
- poor crimps
- loose terminals.
If the A/C fan controller must be replaced, refer to the appropriate Shop Manual for service details.
PART INFORMATION TBALE
| PART NUMBER | PART NAME |
|---|---|
| E8FZ-8B658-A | Fan Controller, Escort |
| E93Z-8B658-A | Fan Controller, Tempo, Topaz |