1996-2002 Ford Explorer - Heat and AC Blend Door Replacement Parts
This is a product developed by the HeaterTreater Engineers for the
common blend door failure problem on 96-01 Explorers (some early 02's
used the same HVAC system. Check photo's to see if your 02 is the
older system). Please check our feedback to get an idea of the product
line integrity and customer reaction to our products. We are committed
to customer satisfaction and successful repairs of blend door
problems.
The HeaterTreater
replaces the plastic blend door with steel. Replacing the existing door
with another plastic door is at best a stop-gap solution. The failure
is a result of excessive forces in the operation of the blend door.
Modifying the top or bottom axle contact points will further weaken the
system and result in faster failure of plastic components.
Replacing the plastic
door is only solving the symptoms of the problem. The same system
design problem that caused the failure in the first place WILL re-occur
over time. The HeaterTreater attacks the root cause of the failure by
constructing hardware that is designed to meet the rigors of normal
operation of the HVAC system, and last for the life of the
automobile. The kit includes detailed instructions and all
hardware required to complete the fix, including dremel bits and metal
tape to seal the cut.
This is a kit to do a
complete repair on the blend door malfunction that is common to 96-2001
Ford Explorers. Every Explorer in this range either has, or
will have, this common failure. The pictures show the hardware
provided for the fix. All work is done through the glove
compartment opening and a Dremel cut in the bottom of the heater
box...no removal of the dash panel or evacuating the AC system and
draining the radiator. Once completed, the alterations are under
the dash panel in the foot area and are not visible. The work to
install the fix is relatively simple and can be accomplished by the
average shade tree mechanic. The work could easily be done by any local
independent garage. Product returns are accepted within three weeks for
a full refund(minus shipping).
The standard fix for
the blend door failure is to remove the heater box and replace the
plastic door. If the instructions with other fixes start out with
“remove the heater box or dash panel�,
be ready for considerable work. Removal of the box requires removing
the dash panel, evacuating and disconnecting the AC compressor,
draining and disconnecting the heater hoses. Fixing the door is
relatively easy, but the labor(and cost) of getting to the door makes
this a time consuming and expensive job. The HeaterTreater avoids the
hard work by providing a kit that allows the repair to be done with
superior components without having to disassemble the automobile. 1hr
work vs 8-14 hours of work, and no specialized mechanical skills
required.
The Problem:
- The
Explorer is built with a Blend Door to control the heater and AC
function. The blend door controls air flowing through AC
evaporator and diverts it into the vent system or through the heater
coil, or any combination in between. The doors are controlled by
a stepper motor. The issue with the system is that the system has to
calibrate itself and find the end points of movement before the
computer can understand the two closed positions and regulate the
temperature. The photograph shows the blend door actuator motor
for the Explorer. The fan gear is connected to the blend door and the
motor is capable of moving the fan between the constraints of stopping
against the motor case. The fan is a 90 degree fan. When it moves
between the two stop points, it has 90 degrees of movement
capability(180 – 90). The motor is capable of moving
the door through a 90 degree arc, but the door hits the extents of
movement at 50 degrees. The net effect is that the plastic doors have
to absorb the force of the motor driving to a stall point. The
motor is geared to move the doors slowly and with a good amount of
force. The door has to withstand the force of stopping the motor, and
like bending a coat hanger back and forth, will eventually break.
Do you have the problem?
The usual symptom
is an inability to effectively control the temperature of the HVAC
system. The door hangs on a vertical axis, so turning a sharp corner,
or fiddling with the fan speed can swing the door into the hot or cold
position randomly. While the symptoms are fairly conclusive for blend
door failure, the only way to really check it out is to remove the
blend door actuator motor and look at the axle.
You can access the
actuator motor by fully opening the glove box(squeeze the sides of the
box and pull out). The motor is located on top of the heater box behind
the glove box door. There are two motor attachment schemes used on
Ford. The older models used screws mounting the motor directly to the
plenum box. With the screw attachment, you will see two 8mm head
screws(note that a 5/16 socket will also work) in the front of the
motor. These are easy to remove. There is a third screw that is
directly behind the white connector socket that has to be removed with
a thin profile ratchet. Remove the three screws and pry up on the motor
to remove it. The second attachment method used on later models is a
plastic housing that is screwed to the heater box with a plastic pinch
attachment that the motor fits on to. The motor is removed by prying up
first on the front of the motor and when the front connector releases,
pry up on the back connector directly under and behind the white
electrical connector. The motor will just pop out.
The picture of two
blend doors shows the two most common fail modes. In one the motor
connector splits, leaving half of the axle connector. In the other
failure, the motor connector breaks completely off. The split failure
is shown from the top. Once you have removed the motor, you can check
by feel or with a mirror to see if the axle is completely broken off or
has half remaining. Either fail mode indicates a broken blend door.
If either of the fail
modes is evident, this is a conclusive diagnosis that the blend door
needs to be replaced. An alternative that has circulated on the
internet is the “nail fix�. This can
only be attempted with the split axle fail mode. We had our engineer do
an analysis of this repair and the report is posted on our
heatertreater.net web site.
Another reported fail
symptom is a “clicking� sound coming
from behind the glove box. This occurs when the motor gears get out of
alignment and are slipping against each other, making the noise.
Sometimes you can make it stop by pushing down on the back of the motor
and getting the gears to catch. The failure usually occurs with a
broken blend door that allows the motor to get out of alignment and
twist slightly, causing the gears to disengage. The HeaterTreater will
put the system back in alignment and correct this problem.
The HeaterTreater TM Solution:
This kit replaces
the plastic doors and axle with stainless steel components. All
work is done through the glove box opening and no disassembly of the
dash or evacuation of the AC system is required. Tools required
are a screw driver, pair of pliers, and a Dremel tool( if you don't already have one, this is a good excuse and the tool has
many uses. The area under the dash is confined and you will need either
a stubby Dremel tool(~6� long), or a flexible extension
for a larger industrial rotary tool. Target has a new rotary cutter
product from Durabuilt for ~$30 that includes a flexible extension,
variable speed motor, and every grinding bit known to modern Chinese
technology(except the one you really need which is included in the
HeaterTreater kit ).
The repair will take about an hour the first time, and once you have
experience you can do another car in about 45min. No extensive
mechanical skills are required. The picture shows the metal
replacement kit. The plastic door is accessed by using the Dremel
tool and bit to cut into the plastic heater housing from the
bottom. Complete diagrams for the cutting pattern are
provided. It's a very simple process. The broken plastic
door is removed and replaced with the HeaterTreater TM .
The instructions are written with multiple pictures and dual level
instructions. You can read the bold print only for experienced
mechanics or read the bold and standard for full "instructions for
Dummies". The instructions are almost insultingly simplistic for
those who care to read the entire document without admitting that they
did it. The fix is really easy and MUCH preferable to disassembly
of the entire dash and engine cooling systems. We provide support via
email or phone if required. Our goal is to make sure that every
installation is successful. To date we have achieved that goal and have
no intention of letting up. This will solve the problems with the blend
door and is over-engineered to outlast the Explorer. All our
products are designed by degreed professional engineers and
manufactured to exacting specifications. If for any reason the
hardware ever fails it will be replaced at no cost.
100% Made in
Patent Pending
