1991 1999 ford explorer chilton User Manual

							From inside the engine compartment, disconnect the heater hoses from the core fittings ...
Disconnect the heater hoses from the heater core tubes and plug hoses.
2. 
In the passenger compartment, remove the four screws attaching the heater core access cover to the
plenum assembly and remove the access cover.
3. 
... then, in the passenger compartment, remove the under dash cover retaining screws ... HOW TO USE THIS BOOK
674 REMOVAL & INSTALLATION 
						

							... and allow the cover to drop down. If necessary, you can remove the cover if it is in your way
Remove the heater core access panel attaching screws ...
... then remove the cover by pulling downward and straight back to disengage the drain tube (arrow)
Pull the heater core rearward and down, removing it from the plenum assembly.
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REMOVAL & INSTALLATION 675 
						

							Pull the heater core rearward and down to remove it from the plenum assembly
To install:
Position the heater core and seal in the plenum assembly.
1. 
Install the heater core access cover to the plenum assembly and secure with four screws.
2. 
Install the heater hoses to the heater core tubes at the dash panel in the engine compartment. Do not
over-tighten hose clamps.
3. 
Check the coolant level and add coolant as required. Connect the negative battery cable.
4. 
Start the engine and check the system for coolant leaks.
5. 
1991-99 Models
Exploded view of the blower motor housing and the heater air plenum assemblies Click to enlarge
Disconnect the negative battery cable. Allow the engine to cool down. Drain the cooling system to a
level below the heater core fittings on the firewall.
1. 
CAUTION
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When draining the coolant, keep in mind that cats and dogs are attracted by the 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.
Disconnect the heater hoses from the heater core tubes and plug hoses.
2. 
Remove the five nuts that secure the blower motor housing to the firewall.
3. 
Pull the housing away from the firewall. Disconnect any wire harness plugs which inhibit the housing.
4. 
Remove the remaining nuts which secure the heater air plenum (inside the passenger compartment) to
the firewall.
5. 
In the passenger compartment, remove the instrument panel. Refer to Section 10.
6. 
Pull the heater air plenum rearward from the firewall and remove it from the vehicle.
7. 
Remove the heater core from the heater air plenum.
8. 
Inspect all air seals on the components and firewall and replace any that are damaged.
9. 
To install: Install the heater core into the air plenum chamber.
10. 
Position the heater air plenum against the firewall from the passenger compartment.
11. 
Under the hood, install the plenum retaining nuts.
12. 
Install the blower motor housing to the firewall and install the attaching nuts.
13. 
Connect the heater hoses to the heater core tubes at the dash panel in the engine compartment. Do not
over-tighten the hose clamps.
14. 
Install the instrument panel.
15. 
Check the coolant level and add coolant as required. Connect the negative battery cable.
16. 
Start the engine and check the system for coolant leaks.
17. 
Control Head HOW TO USE THIS BOOK
Control Head 677 
						

							Example of the control head and the air flow paths in the plenum assembly (with A/C)
Click to enlarge
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678 REMOVAL & INSTALLATION 
						

							Exploded view of a cable equipped control head
Click to enlarge
Front and rear view of a cableless control head
Disconnect the negative battery cable.
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REMOVAL & INSTALLATION 679 
						

							On 1331-34 models, open the ash tray and remove the 2 screws that hold the ash tray drawer slide to
the instrument panel. Remove the ash tray and drawer slide bracket from the instrument panel.
2. 
On 1335-33 models, remove the radio.
3. 
Gently pull the finish panel away from the instrument panel and the cluster. The finish panel pops
straight back for approximately 1 inch (25.4mm), then up to remove. Be careful not to trap the finish
panel around the steering column.
4. 
If equipped with the electronic 4x4 shift-on-the-fly module, disconnect the wire from the rear of the
4x4 transfer switch before trying to remove the finish panel from the instrument panel.
Remove the 4 screws attaching the control assembly to the instrument panel.
5. 
Pull the control through the instrument panel opening far enough to allow removal of the electrical
connections from the blower switch and control assembly illumination lamp. Using a suitable tool,
remove the vacuum harness from the vacuum switch on the side of the control.
6. 
If equipped with cables, perform the following: At the rear of the control, using a suitable tool, release the temperature and function cable
snap-in flags from the white control bracket.
1. 
On the bottom side of the control, remove the temperature cable from the control by rotating
the cable until the T-pin releases the cable. The temperature cable is black with a blue
snap-in flag.
2. 
Pull enough cable through the instrument panel opening until the function cable can be held
vertical to the control, then remove the control cable from the function lever. The function
cable is white with a black snap-in flag.
3. 
7. 
Remove the control assembly from the instrument panel.
8. 
To install: If equipped with control cables, perform the following:Pull the control cables through the control assembly opening in the instrument panel for a
distance of approximately 2 in. (203mm).
1. 
Hold the control assembly up to the instrument panel with its face directed toward the floor of
the vehicle. This will locate the face of the control in a position that is 30 degrees out of its
installed position.
2. 
Carefully bend and attach the function cable that has a white color code and a black snap-in
terminal to the white plastic lever on the control assembly. Rotate the control assembly back
to its normal position for installation, then snap the black cable flag into the control assembly
bracket.
3. 
On the opposite side of the control assembly, attach the black temperature control cable with
the blue plastic snap-in flag to the blue plastic lever on the control. Make sure the end of the
cable is seated securely with the T-top pin on the control. Rotate the cable to its operating
position and snap the blue cable flag into the control assembly bracket.
4. 
3. 
Connect the wiring harness to the blower switch and the illumination lamp to its receptacle on the
control assembly. Connect the terminal on the vacuum hose to the vacuum switch on the control
assembly.
4. 
Position the control assembly into the instrument panel opening and install the 4 mounting screws.
5. 
If equipped, reconnect the 4x4 electric shift harness on the rear of the cluster finish panel.
6. 
Install the cluster finish panel with integral push-pins. Make sure that all pins are fully seated around
the rim of the panel.
7. 
On 1331-34 models, reinsert the ash tray slide bracket and reconnect the illumination connection
circuit. Reinstall the 2 screws that retain the ash tray retainer bracket and the finish panel. Replace the
ash tray and reconnect the cigarette lighter.
8. 
On 1335-33 models, reinstall the radio.
9. 
Connect the negative battery cable and check the heater system for proper control assembly operation.
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Control Cables
ADJUSTMENT
Function Selector and Temperature Selector Control Cable
To check the temperature cable adjustment, move the temperature control lever all the way to the left, then
move it all the way to the right. At the extreme ends of lever travel, the door should be heard to firmly seat,
indicated by a loud thumping sound, allowing either maximum or no air flow through the heater core. To
check the function cable adjustment, see that the function lever will reach the detents at the far left and right
of its travel. In addition, check that the air flow is correct when the function lever is moved through each
detent provided in the control assembly. If cable adjustment is needed, proceed as follows:
Disengage the glove compartment door by squeezing its sides together. Allow the door to hang free.
1. 
Working through the glove compartment opening, remove the cable jacket from the metal attaching
clip on the top of the plenum by depressing the clip tab and pulling the cable out of the clip.
2. 
The adjustable end should remain attached to the door cams. To adjust the temperature control cable, set the temperature lever at COOL and hold. With the cable
end attached to the temperature door cam, push gently on the cable jacket to seat the blend door. Push
until resistance is felt. Reinstall the cable to the clip by pushing the cable jacket into the clip from the
top until it snaps in.
3. 
To adjust the function control cable, set the function selector lever in the DEFROST detent and hold.
With the cable end attached to the function cam, pull on the cam jacket until cam travel stops.
Reinstall the cable to the clip by pushing the cable jacket into the clip from the top until it snaps in
place.
4. 
Install the glove compartment.
5. 
Run the system blower on HIGH and actuate the levers, checking for proper adjustment.
6. 
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Control Cables 681 
						

							Control cable connections at the head and the air plenum
Click to enlarge
Control cable routing diagram Click to enlarge
Temperature and Function Cables Disconnect the negative battery cable.
1. 
Remove the control assembly from the instrument panel.
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							Disengage the glove compartment door by squeezing the sides together and allowing the door to hang
free.
3. 
Working through the glove compartment and/or control opening, remove the temperature and
function cable jackets from their clips on top of the plenum by compressing the clip tans and pulling
the cables upward.
4. 
Reach through the glove compartment opening and disconnect the function and temperature cables
from their separate cams. The cable ends are secured to the cams under a retention finger.
5. 
The cables are routed inside the instrument panel with 2 routing aids. Remove the cables from these
devices. Reaching through the control opening, pull the cables upward out of the wiring shield
cut-out. Reaching through the glove box opening, pull the cables out of the plastic clip up inside the
instrument panel.
6. 
Pull the cables from the instrument panel through the control assembly opening.
7. 
To install: Working through the glove compartment opening and the control opening in the instrument panel,
feed the end of the cables to the cam area. Feed the cables in from the glove compartment opening,
making sure the coiled end of the white function cable and the round hole diecast end of the
temperature cable go in first.
8. 
Attach the coiled end of the function cable to the function cam, making sure the cable is routed under
the cable hold-down feature on the cam assembly. The pigtail coil may be facing either up or down.
9. 
Attach the diecast end of the temperature cable to the temperature cam making sure the cable is routed
under the cable hold-down feature on the cam assembly.
10. 
Route the control end of the cable through the instrument panel until the ends stick out of the control
opening. It is not necessary to insert the cable into any routing devices previously used. The routing
aids are only necessary when the entire instrument panel is removed and reinstalled.
11. 
Attach the function and temperature cables to the control. Install the control assembly in the
instrument panel.
12. 
Adjust the cables in their clips on top of the plenum.
13. 
Make sure the radio antenna cable does not become disengaged from its mounting and fall into the
plenum cam area where it could cause an increase in control assembly operating effort or a faulty
selection of system functions.
Connect the negative battery cable and make a final check of the system for proper control cable
operation.
14. 
Air Conditioning Components
REMOVAL & INSTALLATION
Repair or service of air conditioning components is not covered by this manual, because of the risk of
personal injury or death, and because of the legal ramifications of servicing these components without the
proper EPA certification and experience. Cost, personal injury or death, environmental damage, and legal
considerations (such as the fact that it is a federal crime to vent refrigerant into the atmosphere), dictate that
the A/C components on your vehicle should be serviced only by a Motor Vehicle Air Conditioning (MVAC)
trained, and EPA certified automotive technician.
If your vehicles A/C system uses R-12 refrigerant and is in need of recharging, the A/C system can be
converted over to R-134a refrigerant (less environmentally harmful and expensive). Refer to Section 1
for additional information on R-12 to R-134a conversions, and for additional considerations dealing
with your vehicles A/C system. HOW TO USE THIS BOOK
Air Conditioning Components 683