A/C - Poor Performance Diagnosis
Article No. 86-20-2AIR CONDITIONING - DEALER INSTALLED - POOR PERFORMANCE - DIAGNOSTIC PROCEDURES
FORD 1986 ESCORT, TEMPO
LINCOLN-MERCURY 1986 LYNX, TOPAZ
The following procedures should be used when diagnosing concerns of poor performance with Ford (dealer installed) "add on" air conditioning. It is important that these steps be used prior to component replacement.
1. Verify that the thermostat switch capillary tube relocation has been performed. (All dealer letter February 1986.)
2. Check the engine cooling system for low coolant level and possible drive belt slippage.
3. Check for proper A/C charge. Operate the A/C system for five minutes, observe the sight glass for freon bubbles at normal and high idle. If bubbles are present, add freon until the sight glass becomes bubble-free and then add an additional 1 ounce of freon.
4. Check compressor/clutch operation by setting function control lever in "Panel" position and temperature control lever in "Cool" position. Engage and disengage A/C push button and check A/C compressor/clutch cycling.
5. Check to make sure the recirculation door on the evaporator assembly remains open when the A/C push button is engaged. A malfunctioning vacuum check valve will allow the recirculation and fresh air doors to change position during periods of low vacuum. This allows fresh air to enter the system and raise register temperatures.
6. Check that the electric cooling fan is operating with A/C engaged.
7. Check that the evaporator case fits evenly and securely against heater blower inlet. If not, loosen lower right hand side evaporator mounting bracket and reposition evaporator assembly to heater blower assembly.
8. Check for even air flow from all register openings. An uneven air flow indicates improper adjustment of mode selector door cable in "Panel" position.
This causes partial air blockage to passenger right side register. Adjust mode selector door cable as follows:
a. Place mode selector lever in "Panel" position.
b. Hold mode selector actuator assembly on heater case securely, and push mode selector lever towards "Off". Do not allow mode selector door to move. This will allow the cable to slip through the self-adjusting clip.
c. Release mode selector assembly, and move mode selector lever to "Defrost" position, then return lever to "Panel" position. This will adjust the mode selector assembly and restore proper air flow to the passenger side registers.
9. Check for proper installation of condenser seals and radiator air dam. (Tempo/Topaz vehicles only.)
10. Road test vehicle after above installation checks have been completed and adjustments made where indicated. Set blower speed on "High", set temperature selector lever to maximum cool position and monitor center left register temperature. If an acceptable register temperature is not reached after 8-10 minutes of stop and go city driving (45 mph (72 km/h) or less) or 15-20 minutes of highway driving (45 mph (72 km/h)), proceed to Step 11. If acceptable register temperatures are obtained, no further actions are necessary.
11. Discharge A/C system and replace existing expansion valve with new E6FZ-19849-B expansion valve. Recharge A/C system with 2 lbs. 2 oz. of freon and again road test the vehicle as indicated above.
NOTE: Rapid A/C clutch cycling (5-8 seconds) at lower blower speeds, or no A/C clutch cycling also indicates malfunctioning expansion valve.
PART NUMBER PART NAME CLASS
E6FZ-19849-B Expansion Valve B
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
"Actual Time" as defined in the Warranty and Policy Manual. DLR. CODING: Basic Part No. 19849 - Code: 53