QuestionHi,
My 1999 Dodge Ram 1500 Conversion van has a AC and heater core problem. Long story short is I need to remove/replace the AC evaporator (the thing that looks like a small radiator)due to leakage. The heater core is also suspect for leakage. AC doesn't work and bad odor from the leaking AC oil in the system. This problem has been confirmed when the A/C / heater core housing had been propped open enough to see /feel oil collecting in the housing. Now the problem. It has been impossible for me to access all the bolts that attach the AC housing from the engine compartment. Not enough clearance to get hand or tools to the rear of the housing. I was thinking maybe this housing needs to be accessed and unbolted from the inside of the firewall. Does this mean I need to pull the entire dash to get to the mounting bolts? Any other suggestions. AC repair shop quotes from 750 - 1250.oo but I would like to do it myself and save the labor costs. Parts run maybe 300.00 at most.
AnswerHEATER-A/C HOUSING
WARNING:
REVIEW THE WARNINGS AND CAUTIONS IN THE FRONT OF THIS GROUP BEFORE PERFORMING THE FOLLOWING OPERATION.
ON VEHICLES EQUIPPED WITH AIRBAGS, Refer to PASSIVE RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
REMOVAL
Disconnect and isolate the battery negative cable.
If the vehicle is not equipped with air conditioning, go to Step 5. If the vehicle is equipped with air conditioning, disconnect the suction line jumper at the expansion valve. See Suction Line Jumper in the Removal and Installation section of this group for the procedures.
Remove the screws that secure the filter-drier and its mounting bracket to the heater-A/C housing and the cowl side panel. Swing the filter-drier, mounting bracket and refrigerant plumbing as a unit out of the way towards the center of the vehicle. See Filter-Drier in the Removal and Installation section of this group for the procedures.
Unplug the wire harness connector from the fin sensing cycling clutch switch.
Unplug the wire harness connectors from the blower motor resistor, and the high speed blower motor relay.
Place waterproof material over the generator, to protect it from spilled engine coolant.
Drain the engine cooling system. Refer to Cooling System for the procedures.
Disconnect the heater hoses from the heater core tubes. Refer to Cooling System for the procedures. Install plugs in, or tape over the opened heater core tubes.
Remove the right headlamp assembly, the grille panel, the right cowl grille support panel, and the right radiator core support assembly. Refer to Body for the procedures.
Remove the two screws that secure the lower heater-A/C housing flange to the blower housing Heater-A/C Housing Remove/Install
Disconnect the link from the blend-air door motor on the top of the distribution duct in the passenger compartment. See Blend-Air Door Motor in the Removal and Installation section of this group for the procedures.
From the passenger compartment, reach through the instrument panel glove box opening to access and remove the two stamped nuts and one screw that secure the heater-A/C housing to the dash panel below the distribution duct.
From the passenger compartment, reach through the instrument panel glove box opening to access and remove the two stamped nuts that secure the heater-A/C housing to the dash panel above the distribution duct.
From the engine compartment, remove the one stamped nut that secures the heater-A/C housing to the stud on the dash panel.
Carefully separate the lower heater-A/C housing flange from the blower housing.
Pull the heater-A/C housing away from the dash panel until the blend-air door link is clear of the hole in the dash panel.
Remove the heater-A/C housing from the engine compartment.
DISASSEMBLY
Place the heater-A/C housing on a work bench, with the heater-A/C housing top cover facing up.
Remove the nut that secures the lever to the blend-air door pivot shaft Blend-Air Door Linkage
Disengage the boot for the blend-air door link from the rear mounting flange of the heater-A/C housing.
Remove the blend-air door link, boot and lever from the heater-A/C housing as a unit.
Remove the screw that secures the high speed blower motor relay mounting bracket to the heater-A/C housing and remove the relay and bracket Heater-A/C Housing Top Cover Remove/Install
Remove the screws that secure the top cover to the heater-A/C housing.
Remove the top cover from the heater-A/C unit.
INSPECTION
Examine all of the heater-A/C housing seals for damage. Replace all damaged or deformed seals. Clean all of the heater-A/C mounting flanges and apply new sealant prior to reassembly.
Inspect the evaporator coil and heater core for bent fins or other damage. Remove any foreign material or other restrictions to air flow. Repair or replace any faulty or damaged components as required.
ASSEMBLY
Position the top cover onto the heater-A/C unit. Be certain that the blend-air door pivots, all seals, and the grommet for the fin sensing cycling clutch switch wire harness are properly positioned.
Secure the top cover to the heater-A/C housing with screws. Tighten the mounting screws to 2.2 N·m (20 in. lbs.)
Rotate the blend-air door pivot shaft back and forth to confirm that the door moves freely throughout its travel. If there is any binding or interference, remove the top cover from the heater-A/C housing and repair as required.
Reinstall the blend-air door lever, link, and boot unit to the heater-A/C housing. Be certain that the boot flange is properly seated in the hole on the rear mounting flange of the housing.
Reinstall the lever to the blend-air door pivot shaft and secure it to the shaft with a nut.
Position the high speed blower motor relay and mounting bracket to the heater-A/C housing and secure it with a screw. Tighten the mounting screw to 2.2 N·m (20 in. lbs.)
INSTALLATION
Position the heater-A/C housing to the dash panel. Be certain that the blend-air door link and the housing studs are inserted through the proper holes in the dash panel.
Secure the lower heater-A/C housing flange to the blower housing with two screws. Tighten the mounting screws to 2.7 N·m (24 in. lbs.)
Secure the heater-A/C unit to the stud on the engine compartment side of the dash panel with a nut. Tighten the mounting nut to 4.5 N·m (40 in. lbs.)
From the passenger compartment, reach through the instrument panel glove box opening to install the two nuts that secure the heater-A/C housing studs on the dash panel above the distribution duct. Tighten the mounting nuts to 4.5 N·m (40 in. lbs.)
From the passenger compartment, reach through the instrument panel glove box opening to install the two nuts and the screw that secure the heater-A/C housing to the dash panel below the distribution duct. Tighten the mounting nuts to 4.5 N·m (40 in. lbs.) Tighten the mounting screw to 2.7 N·m (24 in. lbs.)
Connect the link to the blend-air door motor. See Blend-Air Door Motor in the Removal and Installation section of this group for the procedures.
Reinstall the right radiator core support assembly, the right cowl grille support panel, the grille panel, and the right headlamp assembly. Refer to Body for the procedures.
Unplug or remove the tape from the heater core tubes. Connect the heater hoses to the heater core tubes and fill the engine cooling system. Refer to Cooling System for the procedures.
Plug in the wire harness connectors to the blower motor resistor and the high speed blower motor relay.
If the vehicle is not equipped with air conditioning, go to Step 13. If the vehicle is equipped with air conditioning, plug in the wire harness connector to the fin sensing cycling clutch switch.
Reconnect the suction line jumper to the expansion valve. See Suction Line Jumper in the Removal and Installation section of this group for the procedures.
Reinstall the screws that secure the filter-drier and its mounting bracket to the cowl side panel and the heater-A/C housing. See Filter-Drier in the Removal and Installation section of this group for the procedures.
Connect the battery negative cable.
Start the engine and check for proper operation of the heating and air conditioning systems.
