Evaporator Temperature Sensor / Switch: Service and Repair

Fig. 7 Exploded view of evaporator & heater core.:

Fig. 8 Exploded view of instrument panel assembly.:

Fig. 9 Instrument panel retaining bolt locations.:

Electronic Thermostat, Evaporator Core and/or Expansion Valve

1. Disconnect battery ground cable and discharge A/C system.
2. Disconnect refrigerant lines and vacuum hose at firewall connector, Fig. 7.
3. Refer to Fig. 8, and remove instrument panel as follows:
a. Remove horn button cover and steering wheel retaining nut, mark position of steering wheel, then remove wheel using suitable puller.
b. Remove parcel tray and combination gauge cluster, if equipped.
c. Remove cluster retaining screws and instrument cluster bezel, disconnect electrical connectors and speedometer cable, then pull cluster from dash.
d. Disconnect electrical connectors and remove radio assembly, if equipped.
e. Remove heater control assembly as outlined.
f. Remove glove compartment assembly.
g. Remove side ventilator ducts and side defroster grilles.
h. Pry up caps concealing instrument panel retaining bolts, Fig. 9, then remove ten bolts and instrument panel.
4. Disconnect electrical connector to evaporator relay.
5. Remove evaporator retaining nuts and the evaporator assembly, Fig. 7.

Fig. 10 Exploded view of evaporator core assembly.:

6. Carefully remove foam insulation from evaporator case inlet and outlet, Fig. 10.
7. Remove case retaining clips and separate upper and lower case halves, taking care not to damage thermostatic sensor.
8. Remove evaporator along with expansion valve from lower case.
9. Remove expansion valve capillary bulb from evaporator core.
10. Disconnect expansion valve and equalizer tube from evaporator, then remove valve and discard O-rings. If evaporator is to be replaced, add 1.7 oz. new refrigeration oil to replacement evaporator.
11. Reverse procedure to install, noting the following:
a. Use new O-rings lightly lubricated with refrigeration oil when making refrigerant line connections.
b. Ensure sensor bulb and case seals are properly aligned prior to installation.

12. Evacuate and recharge system, then check for leaks.