A/C - Insufficient Cooling
Article No. 86-24-4AIR CONDITIONING - INSUFFICIENT COOLING - VEHICLES BUILT PRIOR TO JULY, 1986
FORD 1986 TAURUS
LINCOLN-MERCURY 1986 SABLE
Vehicles built prior to July, 1986 may have insufficient A/C cooling when the selector is positioned on MAX A/C. This may be caused by an incorrect refrigerant charge and/or air leakage through the heater core. To correct this, check to make sure the refrigerant charge is correct and install a new Heater Water Control Valve, D4AZ-18495-A, using the following diagnostic/service procedure:
Insufficient A/C Cooling Diagnostic and Service Procedure
1. Check the radiator and condenser to make sure they are free of damage and/or blockage.
2. Check the engine electric cooling fan to make sure it is operating when the A/C is turned on. Repair as necessary. Refer to TSB 86-15-2.
3. Check the temperature control knob on the control assembly to make sure it is adjusted correctly. The procedure for this check is:
a. Rotate the temperature control knob fully clockwise to the maximum heat position. Let the knob go. It should spring back from the end.
b. Rotate the temperature control knob fully counterclockwise to its maximum cool position. Let the knob go. It should spring back.
c. Repeat the check for spring-back action of the temperature control knob travel two more times.
4. After checking the temperature control cable adjustment (and adjusting if necessary), check the temperature at the center register opening. The temperature should be below 45~F at 70~F ambient when set for MAX A/C and the temperature control knob set at maximum cooling.
5. If the temperature is above 45~F at an ambient of 70~F, clamp off the water flow through the heater core inlet hose with hose clamping pliers. Then, operate the system for 5 minutes to allow the system to stabilize and recheck the temperature at the center register.
6. If the temperature is still above 45~F at an ambient of 70~F, check the refrigerant system pressures and compare them to those given in the 1986 Taurus/Sable Shop Manual, Section 36-32-8. If the pressures are within specification, discharge and evacuate the refrigerant system. Then, recharge the refrigerant system with 44 ounces of R-12 using a charging cylinder or a charge-station. DO NOT recharge the system using 14 ounce cans.
7. If the temperature is below 45~F at an ambient of 70~F, install a water control valve in the heater core inlet hose.
Water Control Valve Installation Procedure
1. Disconnect the negative (ground) cable from the battery.
2. Drain one gallon of coolant from the radiator into a clean container. Save the coolant.
Figure 2:
3. Cut the inlet hose to the heater core to allow installation of the water control valve, see Figure 2.
a. For the 2.5L engine, remove a 1 inch to 1-1/4 inch section of hose.
b. For the 3.0L engine, cut the hose as shown in one location only.
NOTE: Prior to installing the water control valve, note the coolant flow direction shown by the arrow on the water control valve.
4. Place a hose clamp over each open end of the cut hose, install the water control valve, D4AZ-18495- A, between the sections of hose. Then tighten each hose clamp to 12-18 in.lbs. (1-2 N-m).
5. The water control valve is operated by a vacuum motor. To provide vacuum to the motor, proceed as follows:
a. Remove the radio applique and the four screws which secure the radio to the instrument panel and remove the radio.
b. Obtain a piece of service hytrel plastic tubing, E25Y-19C828-A, and clip off the end fittings. Start feeding the tubing from the engine compartment side of the dash panel into the passenger compartment. Pass the tube through the foam insulator at the same point where the evaporator case vacuum source tube enters the passenger compartment. Push the tube through the insulator until a 6 inch section remains in the engine compartment.
c. Connect the hytrel plastic tubing to the vacuum motor on the water control valve. A piece of 1/8 inch I.D. vacuum hose, approximately 1 inch long should be installed between the hytrel plastic tubing and the water control valve to allow the connection.
Figure 2:
d. Working inside the passenger compartment, locate the recirculating door vacuum motor and its hose (white stripe) from the vacuum source. Cut the hose and insert a 1/8 female "T" connector as shown in Figure 2.
e. Connect the loose end of the hytrel plastic tubing to the tee.
6. Replace the radio and radio applique.
7. Fill the radiator with the coolant that was drained from the radiator in Step 2.
8. Check the system for proper operation and performance.
PART NUMBER PART NAME CLASS
D4AZ-18495-A Heater Water Control A
Valve
E25Y-19C828-A Hytrel Plastic Tubing C
OTHER APPLICABLE ARTICLES: 86-15-2
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP19831A86 - A/C cooling diagnostics (includes recharge A/C).
TIME: 1.0 Hr.
OPERATION: SP19831B86 - A/C cooling diagnostics and water valve installation (includes recharge A/C).
TIME: 1.7 Hrs. DLR. CODING: Basic Part No. 18495 - Code: 35