A/c-Heater System - Manual — Ford Tempo I (1983-1994)

DESCRIPTION

CAUTION

When discharging air conditioning system, use only approved refrigerant recovery/recycling equipment. Make every attempt to avoid discharging refrigerant into the atmosphere.

This A/C-heater system is an integral system with evaporator case mounted below instrument panel in the passenger compartment. Refrigerant system is a fixed orifice tube cycling clutch type, using a multi-pass evaporator core and a Nippondenso 10-cylinder, swash-plate compressor. The compressor holds up to 5.0 ounces of refrigerant oil. Three control cables are used to control system airflow, temperature regulation and outside or recirculated air source. Major system components include a compressor, condenser, evaporator, suction accumulator/drier and refrigerant lines.

All models incorporate a cooling fan the comes into operation whenever coolant temperatures reach 210°F (117°C). It is controlled by a fan controller. System operation is controlled by the fixed orifice tube and clutch cycling pressure switch. System protection is provided through a high pressure relief valve, which shuts down current to the compressor magnetic clutch, if pressure gets over 450 psi (31.6 kg/cm 2 ).

Temperature Lever

Temperature lever operates a blend-air door through a cable. Air is directed around and/or through the heater core to control discharge air temperature. When the temperature lever is in the "COOL" position, all air flow is directed around heater core. In the "WARM" position, all air flow is directed through heater core. In intermediate positions, air is directed both through and around heater core and mixed to produce air of desired temperature.

Mode Control Lever

Mode control lever operates a control cable connected to a cam on left side of evaporator assembly. The cam operates floor-defrost door and panel-defrost door, depending upon the position of mode control lever. Lever also controls blower on-off switch and A/C clutch operating circuit.

Air Door Lever

Air door lever operates a outside-recirculation door through a cable. Air door lever provides choice of outside air entry or inside air recirculation.

A/C Push Button Switch

The A/C push button switch is for on-off operation of air conditioning compressor clutch circuit.

Blower Switch

Blower switch is used to select "LO", "HI" and 2 intermediate positions. Blower motor fan operates at one of 4 speeds selected.

Cooling Fan Controller

A cooling fan controller is used with all models equipped with A/C, to control engine cooling fan operation. The system components consist of a cooling fan and electric motor connected to the fan shroud, coolant temperature sensor mounted in the thermostat housing, cooling fan controller and relay. Whenever the coolant temperature is above 210°F (117°C) with the ignition switch in the RUN" position (Tempo and Topaz only) the cooling fan controller signals the cooling fan motor to operate. The engine cooling fan should operate during A/C compressor operation and should cycle on and off with the compressor clutch.

The cooling fan controller is located below the instrument panel forward of the evaporator mounting bracket on Escort models. On Tempo and Topaz models the controller is located on the right side cowl panel under the instrument panel and can be serviced through the glove box opening. Each cooling fan controller has the part number stamped on the housing. It is important that the correct controller be installed for proper operation.

FIXED ORIFICE TUBE

The fixed orifice tube assembly is the restriction between high and low-pressure liquid refrigerant. It meters the flow of liquid refrigerant into the evaporator core. The fixed orifice tube is located in the liquid line at the condenser connection and has filter screens on the inlet and outlet ends of the tube body. Adjustments or repairs cannot be made to the orifice tube and to replace it, you must remove and replace the liquid line as well.

MODE & TEMPERATURE CONTROL CABLES

Temperature control cable is self-adjusting with the movement of temperature lever to end of slot in the bezel face of the control assembly. To prevent kinking of the control wire during installation, a preset adjustment should be made before attempting the self-adjusting operation. The preset adjustment may be performed either with cable installed or before cable installation.
Insert end of a small pocket screwdriver into wire loop end of control cable located at the door arm crank. Slide the self-adjusting clip down the control wire (away from either loop) approximately one inch.
With selector lever in maximum down position, insert cable housing into mounting bracket hole and snap into place. Attach self-adjusting clip in door arm crank. Move selector lever to end of slot in bezel face of control assembly to position self-adjusting clip. Check for normal operation. (Scheme 13)

Control Cable Adjustment (Use the same adjustment procedure on mode and temperature control cables.). Scheme 13

Scheme 13: Control Cable Adjustment (Use the same adjustment procedure on mode and temperature control cables.)

TROUBLE SHOOTING

Note. See MANUAL A/C-HEATER SYSTEMS, FORD MOTOR CO. PASSENGER CARS & TRUCKS, TROUBLE SHOOTING article in this section. For cooling fan trouble shooting see GENERAL SERVICING section.

FIXED ORIFICE TUBE R & I

Note. When replacing fixed orifice tube, the high pressure refrigerant line must be replaced. It is an integral part of refrigerant line.

Removal

Discharge A/C system using approved refrigerant recovery/recycling equipment. Disconnect evaporator end of high pressure refrigerant hose using a wrench on each side of evaporator fittings. Cap evaporator tube opening. (Scheme 14)
Disconnect condenser end of the refrigerant line which is connected with spring-locked couplings. (Scheme 16) Attach Spring-Lock Coupling Tool (T81P-19623-G) to release spring. Close tool around coupling and push into cage toward condenser.
Pull hose away from condenser and unclamp tool from disconnected coupling. To install new high pressure refrigerant line, use new "O" rings lubricated with refrigerant oil. (Scheme 16)

Note. Do not use standard "O" rings in spring lock couplings. Use only "O" rings (E35Y-19D690-A).

Installation

Install new garter spring if damaged or missing. Clean refrigerant line fittings. Connect end of high pressure refrigerant line to evaporator fitting. Lubricate condenser end fittings with refrigerant oil.
Push refrigerant line fitting into condenser line with a slight twisting motion. Make sure garter spring is over flared end of refrigerant line to ensure coupling engagement. Charge A/C system.

Scheme 14

SUCTION ACCUMULATOR/DRIER R & I

Discharge A/C system using approved refrigerant recovery/recycling equipment. If equipped with air pump, remove air pump from engine. Disconnect suction hose at accumulator. Disconnect accumulator/drier inlet hose. If equipped with spring lock coupling, use Spring-Lock Coupling Tool (T81P-19623-G) to disconnect inlet hose. (Scheme 16) Disconnect accumulator inlet tube from evaporator core and plug openings. (Scheme 14)
Disconnect wiring harness connector from pressure cycling switch on top of accumulator. Remove screws attaching 2 strap clamps to accumulator bracket and remove accumulator along with suction hose.

To install, reverse removal procedure, using new "O" rings lubricated with clean refrigerant oil. Add one ounce clean refrigerant oil to accumulator.

PRESSURE CYCLING SENSING SWITCH R & I

Note. Discharging the A/C system is not necessary due to the Schrader valve type fitting.

Disconnect wiring connector from the switch. Unscrew switch from top of accumulator. To install, use new "O" ring on the accumulator nipple lubricated with refrigerant oil. Screw in switch. Check for leaks.

COMPRESSOR R & I

Discharge refrigerant using approved refrigerant recovery/recycling equipment. Disconnect electrical wiring from field coil connector. Remove discharge line from manifold and tube assembly using Spring-Lock Coupling Tool (T81P-19623-G2).
On 2.3L engines, remove suction line from suction manifold. Loosen 2 idler attaching screws and release compressor belt tension. Raise vehicle and remove 4 compressor mounting bolts. (Scheme 15) Remove 2 screws attaching heater water return tube to underside of engine supports. To install, reverse removal procedure.

Scheme 15

CONDENSER R & I

Note. Whenever the compressor is replaced, it will be necessary to replace the suction accumulator/drier.

Discharge A/C system using approved refrigerant recovery/recycling equipment. Drain cooling system. Remove ignition coil from engine. Remove screw and nut retaining fan shroud to radiator. Disconnect A/C discharge line retaining clip from radiator fan shroud. Disconnect fan motor wiring and remove fan shroud.
Disconnect upper coolant hose from radiator and lower coolant hose from water pump. If equipped with automatic transaxle, disconnect and plug transmission oil cooler line on transaxle. Remove 2 retaining bolts and remove radiator and lower hose as an assembly.
Disconnect refrigerant line and compressor discharge line at condenser. Both lines are connected with spring-locked couplings. (Scheme 16) Attach Spring-Lock Coupling Tool (T81P-19623-G) to release spring.
Close tool around coupling and push into cage toward condenser. Pull hose away from condenser and unclamp tool from disconnected coupling. Remove condenser upper bracket attaching screws. Remove condenser.

To install, reverse removal procedure. Make sure to add one ounce of clean refrigerant oil to condenser. Use new "O" rings lubricated with clean refrigerant oil.

Note. Do not use standard "O" rings in spring lock couplings. Use "O" rings (E35Y-19D690-A) only.

Spring Lock Coupling & Tool (Use Spring-Lock Coupling Tool (T81P-19623-G) to release spring.). Scheme 16

Scheme 16: Spring Lock Coupling & Tool (Use Spring-Lock Coupling Tool (T81P-19623-G) to release spring.)

COOLING FAN CONTROLLER R & I

Open glove box and remove contents. Push sides of glove box liner inward and pull liner from opening. Allow glove compartment and door to hang from hinges.
Working through the glove box opening, remove screw attaching cooling fan controller mounting bracket to cowl top panel. Disconnect electrical connectors and remove controller. To install, reverse removal procedure and check for proper operation.

EVAPORATOR CORE R & I

Note. Prior to replacing an evaporator core, always leak test the core to be certain it is actually leaking. Whenever an evaporator is replaced it will be necessary to replace the suction accumulator/drier.

Scheme 17

Scheme 17: Removal

Disconnect battery negative cable. Discharge refrigerant from A/C system using approved refrigerant recovery/recycling equipment. Drain cooling system. Disconnect heater hoses at heater core and cap openings. Using a wrench, disconnect suction and refrigerant lines. Cap evaporator tube openings.
From inside of vehicle, remove underside and lower instrument panel trim covers. Remove 4 nuts attaching steering column to steering column support. Lower steering column so that steering wheel rests on front seat. Remove nut attaching instrument panel to steering column support bracket at top of steering column opening.
Disconnect center brace from lower flange of instrument panel. Snap out radio speaker opening covers and remove screws in each opening attaching instrument panel to instrument panel. Disconnect speedometer cable from transmission. Disconnect wiring harness from blower motor and resistor.
Move temperature control lever to "COOL" position and air door control lever to "RECIRC" position. Remove courtesy light wiring from right side door switch. Remove one screw attaching each end of instrument panel to lower cowl side panel. Pull instrument panel rearward, disconnecting any wiring as necessary.
Remove screw attaching bottom of evaporator case to instrument panel. Remove instrument panel center brace from cowl top panel. From inside engine compartment, remove 2 nuts attaching evaporator case to instrument panel. (Scheme 17) (Scheme 17): Exploded View of Evaporator Case
Loosen sound insulation from the cowl top panel in area around air inlet opening. Remove 2 screws attaching support bracket and brace to top cowl panel. Lower evaporator case from vehicle. Remove air inlet duct and floor duct from evaporator case. Remove foam seal from evaporator core tubes.
Drill four 3/16" holes on evaporator case (2 on upright tabs and 2 above evaporator core tubes). (Scheme 18) Remove blower motor resistor from evaporator case. Cut top cover of evaporator case with small saw blade between raised outlines. Remove evaporator core.

Removal of Top Evaporator Case Cover (Cut top evaporator case cover to remove evaporator core.). Scheme 18

Scheme 18: Removal of Top Evaporator Case Cover (Cut top evaporator case cover to remove evaporator core.)

To install, reverse removal procedure noting the following conditions: Transfer 2 foam core seals to new evaporator core. Install a spring nut and screw on both upright tabs and 2 drilled holes above evaporator core tubes. see scheme 7 Seal top cover with Caulking Cord Sealer (D9AZ-19560-A) or equivalent. Use same sealer to seal air inlet duct to evaporator case.

Note. Add 3 ozs. of refrigerant oil to accumulator when installing a new evaporator core.

HEATER CORE R & I

Drain coolant from radiator. Disconnect heater hoses from heater core. Working inside vehicle, remove 4 screws attaching floor duct to plenum and instrument panel. Remove 4 screws attaching heater core cover to lower evaporator case. Remove cover and heater core.

To install, reverse removal procedure.

BLOWER MOTOR R & I

Remove glove box door. Remove instrument panel lower reinforcement from instrument panel. Disconnect blower motor wiring at connector. Remove 4 screws attaching blower and mounting plate to evaporator case.
Rotate motor until mounting plate flats clear edge of glove box opening and remove motor. To remove blower wheel, remove hub clamp spring from wheel hub and remove wheel.