Chrysler Full-Size Trucks 1967-1988 Repair Guide

Evaporator Core

Print

REMOVAL & INSTALLATION



1967-72 Models
  1. Using an approved R-12 recovery/recycling station, follow the manufacturer's instructions to discharge the refrigerant. See General Information & Maintenance .
  2.  
  3. Disconnect the battery ground cable.
  4.  
  5. Drain the cooling system.
  6.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the heater hoses at the core tubes. Plug the tubes.
  2.  
  3. Disconnect the refrigerant lines at the evaporator. Use a back-up wrench on each fitting. Cap all openings.
  4.  
  5. Disconnect the vacuum hoses, one from the intake manifold and two from the water valve. Push the hoses into the passenger compartment.
  6.  
  7. Remove the nuts from the mounting studs on the face of the firewall.
  8.  
  9. From inside, remove the glove box and disconnect the actuator vacuum hose cluster from the back of the control switch.
  10.  
  11. Disconnect the control cables.
  12.  
  13. Disconnect all electrical connectors.
  14.  
  15. Remove the ashtray and left cooler duct and the defroster ducts at the left side of the housing.
  16.  
  17. Disconnect the support bracket from the left side of the housing.
  18.  
  19. Remove the 3 retaining screws from the face of the housing and remove the appearance shield. Collapse the distribution duct towards the back of the instrument panel.
  20.  
  21. Remove both windshield wiper arms.
  22.  
  23. Remove the 7 sheet metal screws and lift off the air intake grille from in front of the windshield.
  24.  
  25. Remove the 2 bolts from the support bracket at the back of the blower motor housing.
  26.  
  27. Pull the unit towards the rear of the cab until all studs are clear of the dash panel, then move the unit to the right and tilt it down and out from under the instrument panel.
  28.  
  29. Place the assembly on a clean work surface and remove the front cover.
  30.  
  31. Carefully pull the sensing tube out from the left side of the evaporator.
  32.  
  33. Remove the 11 retaining screws from the top of the housing and lift the cover plate off the housing.
  34.  
  35. Remove one retaining screw under the foam insulator at the core tubes, then carefully lift the evaporator core out of the housing.
  36.  

To install:
  1. Replace all sealing material.
  2.  
  3. Carefully lower the evaporator core into the housing. Install one retaining screw under the foam insulator at the core tubes.
  4.  
  5. Install the cover plate and 11 retaining screws from the top of the housing.
  6.  
  7. Carefully install the sensing tube in the left side of the evaporator.
  8.  
  9. Install the front cover.
  10.  
  11. Position in the cab and on the studs.
  12.  
  13. Install the 2 bolts on the support bracket at the back of the blower motor housing.
  14.  
  15. Install the air intake grille from in front of the windshield. Install the 7 sheet metal screws.
  16.  
  17. Install both windshield wiper arms.
  18.  
  19. Install the distribution duct. Install the appearance shield.
  20.  
  21. Connect the support bracket at the left side of the housing.
  22.  
  23. Install the ashtray and left cooler duct and the defroster ducts at the left side of the housing.
  24.  
  25. Connect all electrical connectors.
  26.  
  27. Connect the control cables.
  28.  
  29. From inside, connect the actuator vacuum hose cluster from the back of the control switch and install the glove box.
  30.  
  31. Install the nuts on the mounting studs on the face of the firewall.
  32.  
  33. Connect the vacuum hoses, one at the intake manifold and two at the water valve.
  34.  
  35. Connect the refrigerant lines at the evaporator. Always use new O-rings coated with clean refrigerant oil. Use a back-up wrench on each fitting.
  36.  
  37. Connect the heater hoses at the core tubes.
  38.  
  39. Fill the cooling system.
  40.  
  41. Connect the battery ground cable.
  42.  
  43. Using an approved R-12 recovery/recycling station, follow the manufacturer's instructions to evacuate and charge the refrigerant system. See General Information & Maintenance .
  44.  

1973-80 Models

See Figures 1, 2 and 3

  1. Using an approved R-12 recovery/recycling station, follow the manufacturer's instructions to discharge the refrigerant system. See General Information & Maintenance .
  2.  
  3. Disconnect the battery ground cable.
  4.  
  5. Disconnect the hoses at the evaporator. Always use a back-up wrench on each fitting. Cap all openings at once!
  6.  
  7. Remove the glove box and ashtray.
  8.  
  9. Remove the right and left air conditioning ducts.
  10.  
  11. Remove the distribution duct.
  12.  
  13. Remove the center air outlet and duct.
  14.  



Click image to see an enlarged view

Fig. Fig. 1: Common air conditioning system-1973-80 models

  1. Disconnect the wiring harness from the resistor.
  2.  
  3. Disconnect the vacuum lines from the rear housing.
  4.  
  5. Remove the 22 screws from the rear housing.
  6.  



Click image to see an enlarged view

Fig. Fig. 2: Blower housing removal and installation

  1. Remove the 2 plugs and, using a long extension, remove the 2 screws from inside the housing.
  2.  
  3. While holding the defroster door in the HEAT position, separate the unit.
  4.  
  5. Remove 2 screws from the engine side of the firewall and 2 screws from each end of the core, then slide out the core.
  6.  

To install:
  1. Slide the core into place, then install 2 screws in the engine side of the firewall and 2 screws in each end of the core.
  2.  



Click image to see an enlarged view

Fig. Fig. 3: Open the evaporator housing to expose the core (coil)

  1. While holding the defroster door in the HEAT position, secure the unit.
  2.  
  3. Using a long extension, install the 2 screws inside the housing. Install the 2 plugs.
  4.  
  5. Install the 22 screws in the rear housing.
  6.  
  7. Connect the vacuum lines at the rear housing.
  8.  
  9. Connect the wiring harness at the resistor.
  10.  
  11. Install the center air outlet and duct.
  12.  
  13. Install the distribution duct.
  14.  
  15. Install the right and left air conditioning ducts.
  16.  
  17. Install the glove box and ashtray.
  18.  
  19. Connect the evaporator hoses. Always use new O-rings coated with refrigerant oil. Always use a back-up wrench on the fittings.
  20.  
  21. Using an approved R-12 recovery/recycling station, follow the manufacturer's instructions to evacuate and charge the system. See General Information & Maintenance .
  22.  
  23. Connect the battery ground cable.
  24.  

1981-88 Models

See Figures 4, 5 and 6

  1. Using an approved R-12 recovery/recycling station, follow the manufacturer's instructions to discharge the refrigerant system. See General Information & Maintenance .
  2.  
  3. Disconnect the battery ground cable.
  4.  
  5. Drain the cooling system.
  6.  
  7. Disconnect the refrigerant lines at the evaporator and the heater hoses at the core tubes. Always use a back-up wrench on the A/C fittings. Plug all the openings at once!
  8.  



Click image to see an enlarged view

Fig. Fig. 4: Exploded view of in-cab air conditioning components-1981-88 models

  1. Remove the drain tube.
  2.  
  3. Position the gearshift and transfer case levers away from the instrument panel.
  4.  
  5. Remove the glove box.
  6.  
  7. Working through the glove box opening, remove the support brace.
  8.  
  9. Remove the ashtray.
  10.  
  11. Remove the 8 screws from the right side of the instrument panel lower reinforcement. Disconnect the ground strap.
  12.  
  13. Remove the center distribution duct.
  14.  
  15. Disconnect the control cables.
  16.  



Click image to see an enlarged view

Fig. Fig. 5: Common heater control unit for 1981-88 vehicles



Click image to see an enlarged view

Fig. Fig. 6: Bi-level heater control unit

  1. Disconnect the vacuum lines.
  2.  
  3. Disconnect the blower motor wires.
  4.  
  5. Disconnect the wiring at the resistor block.
  6.  
  7. Pull the carpet back and make sure that the grommet is free from the firewall.
  8.  
  9. Remove the heater unit retaining screw from the cowl side sheet metal.
  10.  
  11. Remove the 7 mounting nuts from the engine side of the firewall.
  12.  
  13. Remove the unit. You may have to slightly bend the plastic instrument panel trim for clearance.
  14.  
  15. Remove the 10 screws and 3 door cranks and separate the cover from the housing.
  16.  
  17. Carefully slide out the evaporator core.
  18.  

To install:
  1. Install the evaporator core.
  2.  
  3. Install the 7 mounting nuts on the engine side of the firewall.
  4.  
  5. Install the heater unit retaining screw at the cowl side sheet metal.
  6.  
  7. Connect the wiring at the resistor block.
  8.  
  9. Connect the blower motor wires.
  10.  
  11. Connect the control cables.
  12.  
  13. Install the 8 screws at the right side of the instrument panel lower reinforcement. Connect the ground strap.
  14.  
  15. Working through the glove box opening, install the support brace.
  16.  
  17. Install the center distribution duct.
  18.  
  19. Install the glove box.
  20.  
  21. Install the ashtray.
  22.  
  23. Connect the refrigerant hoses at the evaporator. Always use new O-rings coated with clean refrigerant oil. Always use a back-up wrench on the fittings. Connect the heater hoses at the core tubes.
  24.  
  25. Fill the cooling system.
  26.  
  27. Connect the battery ground cable.
  28.  
  29. Using an approved R-12 recovery/recycling station, follow the manufacturer's instructions to evacuate and charge the refrigerant system.
  30.  

 
label.common.footer.alt.autozoneLogo