1997+ Jeep Cherokee HeaterTreater - Heat and AC Blend Door Replacement Parts
This is a new product developed by the HeaterTreater Engineers for the
common blend door failure problem on 97+ Jeep Cherokee. 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.
This
is a kit to do a complete repair on the blend door malfunction that is
common to the 97- 01 Jeep Cherokee. Every Cherokee in this
range either has, or will have, this common failure. The pictures
show the hardware provided for the fix. All work is done from the
foot area of the passenger side of the Jeep, with 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 two 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�, 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
TM
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 Cherokee is built with a Blend Door to control the heater and
AC function. The blend door controls air flow through either the
AC evaporator or the heater coil, or any combination in between.
The doors are controlled by a stepper motor. The issue with the system
is that the drive motor has a wider range of motion than the movement
of the door will allow. At the extents of movement(full heat or
full AC), the motor overdrives the plastic blend door into the the
internal stop point in the heater box until the motor stalls.
This is considerable force on the door and over time, the door cannot
withstand the force and will break. Once the door breaks, you
lose control over the ability to regulate between heat and AC.
- The standard factory fix is to replace the plastic door.
The process entails removing the heater box which requires - removing
steering wheel and steering column, removing radio and all dash panel
control modules, unbolting all attachment points for the dash panel,
evacuating and disconnecting the AC compressor, draining and
disconnecting the radiator, removing engine side bolts that hold the
heater box in place. Once the box is removed, the fix is
relatively simple, but you still have cheap plastic doors and the
problem will occur again. It is not a particularly difficult fix
for an experienced technician, but it is an 8-12hr job plus refrigerant
and anti-freeze and the costs of labor and supplies adds up quickly
into the $800-$1200 range.
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.
The
blend door actuator motor is located in the upper left hand corner of
the passenger side foot well. The picture below show the location
of the motor. The motor is attached with three 5/16"(or 8mm)
screws that can be easily accessed and removed. Once you have
detached the motor, you can turn the HVAC system on and observe the
movement of the motor by turning the temp control knob. You want
to make sure that the motor is moving properly. (if the motor is
broken, we can help with a replacement).
The motor attaches to the blend door using two different connector
schemes depending on the model year as shown in the second
picture. You can grasp the axle with your fingers and feel the
extents of movement of the door by turning the knob. You should
be able to manually regulate between heat and AC by turning the
axle. The door should hit a hard stop point when you turn it to
heat or AC and not have any play beyond that point. If the axle
is broken or feel disconnected from the door, this is a definitive
indication of a broken blend door. It's hard to explain exactly
what it feels like, but you should be able to switch from AC to heat
and feel a solid stop at the max AC and heat positions. If the
system is loose or ineffective, the blend door is the problem and the
HeaterTreater is the solution.
The HeaterTreater
TM
Solution:
This
kit replaces the plastic door and axle with stainless steel components
that can withstand the force and will last longer than the
Cherokee. All work is done from the passenger side foot well, 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. My favorite tool for the work is a
Harbor Freight mini benchtop grinder with a flexible rotary cutter
attachment. #43533. This setup has vaiable speed for the Dremel bits
and is a good little bench grinder for fine metal and polishing work.
). Dremel bits, and all hardware is provided.
The repair will take about an hour the first time, and once you have
experience, 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 Wrangler.
Patent Pending
