Jun 152016

Mode Door ActuatorI have a 2010 jeep liberty and suddenly the heat and A/C stopped working by the control dials and settings. It just blows hot air constantly through defroster


What you have described is a faulty mode door actuator.

The heating and Air Conditioning system uses a reversible, 12-volt direct current (DC) servo motor which mechanically positions the mode-air door. The mode door actuator (1) is located on the driver side of the HVAC housing.

The mode door actuator is interchangeable with the actuators for the blend-air door and the recirculation-air door. Each actuator is contained within a black molded plastic housing. Each with an integral wire connector receptacle (2) and integral mounting tabs (3). This allows the actuator to be secured to the HVAC housing. The mode door actuator output shaft (4) is connected to the linkage that drives the mode-air door. The mode door actuator does not require mechanical indexing to the mode-air doors, as it is electronically calibrated by the A/C-heater control.

How the Mode Door Actuator Works

The mode door actuator is connected to the A/C-heater control. It is connected through the vehicle electrical system by a dedicated two-wire lead and connector of the HVAC wire harness. The floor, defrost and the panel-air doors can be moved in two different directions by the mode door actuator. When the A/C-heater control pulls the voltage on one side of the motor connection high and the other connection low, the mode-air doors will move in one direction. When the A/C-heater control reverses the polarity of the voltage to the motor, the mode-air doors moves in the opposite direction. Furthermore when the A/C-heater control makes the voltage to both connections high or both connections low, the mode-air doors stop and will not move.

The A/C-heater control uses a pulse-count positioning system. This is to monitor the operation and relative position of the mode door actuator and the mode-air doors. The A/C-heater control learns the mode-air doors stop position during the actuator calibration procedure. And will store a diagnostic trouble code (DTC) for any problems it detects in the mode door actuator circuits.

The mode door actuator cannot be adjusted or repaired. It must be replaced if inoperative or damaged because of its design.

Jun 062016

headlight 2007 jeep wrangler How do I access right side headlight bulb?


Headlight 2007 Jeep Wrangler Replacement

  1. Disconnect and isolate the battery negative cable
  2. Remove the grille panel from the front of the vehicle
  3. Remove the four screws (4) that secure the retainer (3) and the headlight unit (2) to the mounting collar (1) on the face of the front end module carrier
  4. Pull the retainer and the headlight unit away from the front of the vehicle far enough to access the wiring connection on the back of the light housing
  5. Disconnect the engine compartment wiring harness connection from the headlight bulb connector receptacle and from the position light bulb pigtail connector (5)
  6. Remove the headlight unit form the vehicle

2007 Jeep Wrangler Grille Removal

2007 jeep wrangler grille removal diagram

  1. Twist the center of the push pin insert to release and remove the six push pin fasteners (1)
  2. Using a trim stick or equivalent, release the lower clips (3) and separate the grille from the front end module
  3. Disconnect the electrical connectors (4)
May 152016

2006 Jeep Liberty Shifter CablesWhen I put my 2006 Jeep Liberty shifter in park I cannot get the key out. I also noticed that I can move the shift from park to reverse without pushing the safety button on the shift. Is this a linkage, computer, or transmission issue.

  1. Shifter
  2. Gearshift Cable
  3. Park-interlock Cable
  4. Shift Cable Seal Plate
  5. Floor Pan


The cable from shifter to ignition broken would cause the key issue. Broken shifter internal parts may be the cause for the ability to shift without pushing button. It appears to be a common problem for the 2004-2006 Jeep Liberty.

Requires replacement of entire center console 2006 Jeep Liberty shifter assembly with an “upgraded/improved” mopar part to fix the known high failure sub assembly (but not available for purchase separately).


May 102016

1998 Jeep CherokeeI have a 98 jeep Cherokee 5 speed manual with a 4.0L the transmission is out in it. was looking to replace it has the AX 15 tranny. I know about the AX 5 and the AX15 tranny but someone told me there was a better option that was a CH and then 3 numbers do you know what tranny that might be


Only know of the AX15, AX5 and the 30RH that came in it.


Distortion of clutch components during installation and the use of non-standard components are common causes of clutch malfunction.

Improper clutch cover bolt tightening can distort the cover. The usual result is clutch grab, chatter and rapid wear.

An improperly seated flywheel and/or clutch housing are additional causes of clutch failure. Improper seating will produce misalignment and additional clutch problems.

The use of non-standard or low quality parts will also lead to problems and wear. Only use recommended factory parts.

A cocked pilot bearing is another cause of clutch noise, drag, hard shifting, and rapid bearing wear. Always use an alignment tool to install a new bearing. This practice helps avoid cocking the bearing during installation.


May 032016

2001 Jeep Grand CherokeeI put a new brake reservoir on my 2001 Jeep Grand Cherokee 4.0 L. I filled it up with brake fluid and then I pumped until I had a pedal but once I started the truck then I had no more pedal? Any answers?


You still have air in the system. You will need to bleed the brakes. Have your assistant hold the brake pedal down, then open the bleeder fitting. Close the fitting before releasing the brake pedal.

brake bleeding

How to Brake Bleeding

  • Clean the master cylinder of excess dirt and remove the cylinder cover and the diaphragm.
  • Fill the master cylinder to the proper level. Check the fluid level periodically during the brake bleeding process and replenish it as necessary. Do not allow the master cylinder to run dry, or you will have to start over.
  • Before opening any of the bleeder screws, you may want to give each one a shot of penetrating solvent. This reduces the possibility of breakage when they are unscrewed.
  • Attach a length of vinyl hose to the bleeder screw of the brake to be bled. Insert the other end of the hose into a clear jar half full of clean brake fluid, so that the end of the hose is beneath the level of fluid. The correct sequence for bleeding is to work from the brake farthest from the master cylinder to the one closest; right rear, left rear, right front, left front.
  • Depress and release the brake pedal three or four times to exhaust any residual vacuum.
  • Have an assistant push down on the brake pedal and hold it down. Open the bleeder valve slightly. As the pedal reaches the end of its travel, close the bleeder screw and release the brake pedal. Repeat this process until no air bubbles are visible in the expelled fluid.
  • NOTE: Make sure your assistant presses the brake pedal to the floor slowly. Pressing too fast will cause air bubbles to form in the fluid.
  • Repeat this procedure at each of the brakes. Remember to check the master cylinder level occasionally. Use only fresh fluid to refill the master cylinder, not the stuff bled from the system.
  • When the bleeding process is complete, refill the master cylinder, install its cover and diaphragm, and discard the fluid bled from the brake system.


May 022016

2002 Jeep Grand CherokeeMy 2002 Jeep Grand Cherokee with a 4.7L engine is over heating, I don’t think my coolant is going through my motor??? The air never gets warm it stays cold. I’ve changed out the water pump and thermostat, no change.


The most common reason would be form being low on coolant that may be from not bleeding the cooling system properly. Locate the cooling system bleed plug. Failure to purge air from the cooling system can result in an overheating condition and severe engine damage.

Cooling System Bleed Plug – Bleeding

  1. Tighten the radiator draincock and the cylinder drain plugs if removed.
  2. Remove the cooling system bleed plug from the upper radiator hose inlet housing (see Fig. 1)
  3. Fill cooling system with 50/50 mixture of coolant and low mineral water content until coolant begins coming out of the cooling system bleed hole. Install the cooling system bleed plug. Fill radiator to top and install radiator cap. Add sufficient coolant to the overflow tank till it reaches the FULL mark.
  4. With the heater control unit in the HEAT position, operate the engine with radiator cap in place. After engine has reached normal operating temperature, shut engine off and allow to cool. When engine is cooling down, coolant will be drawn into the radiator from the overflow tank.
  5. Add coolant to the overflow tank as needed. Only add coolant to the overflow tank when the engine is cold. Coolant level will be higher when the engine is warm due to thermal expansion. To purge the cooling system of all air, this heat up/cool down cycle (adding coolant to cold engine) must be repeated three times. Add necessary coolant to raise tank level to the FULL mark after each cool down period.

cooling system bleed plug jeep grand cherokee 4.7L engine

The engine overheating may be from being low on coolant and if it is not, It may be from the cooling fans not coming on if electronic or failed clutch fan assembly. As for warm air not coming out the dash, it may be caused by a clogged heater core or an issue with the ventilation system such as a failing blend door actuator. Failed Actuators are common on Chrysler products.

The blend door for all models is actuated by an electric actuator, while the AZC system uses 2 separate actuators to allow the driver and passenger to select individual comfort levels.

The mode door actuators for vehicles equipped with the standard equipment manual temperature control system are vacuum controlled. The optional Automatic Zone Control (AZC) system uses electric motors to actuate all mode doors. The service procedures for both types of actuators are covered by the following procedures.

Dec 102015

Gas tank was replaced today, but car doesn’t start or run like it used to. Should I allow time for engine to adjust or should it not matter? My car almost stopped in the middle of traffic on half a tank of gas in it. I paid $500 to get the gas tank replaced but I feel cheated. Should I be worried ?