heater & ac

2002 liberty 3.7
I have been having a problem with barely warm heat & barely cool ac . I have finally isolated the problem . The blend door actuator turns the blend door but not far enough either way . I removed the actuator [ left it wired up ] & turned the switch knob for it while watching the piece that turns the blend door .
With each click of the knob the actuator moves a very small amount & stops . When turning the knob from full hot to full cold or the opposite , the actuator only turns about 1/8 turn & stops .
I made a 1-1/4 " hole in the heater case with a hole saw & I can see the blend door through this hole . With the actuator removed I can stick my finger through this hole & freely move the blend door from stop to stop . Doing this I get full heat & ac .
My question is , what controls how much the actuator is supposed to turn ? The actuator itself , the control knob or the ecm / computer ? I have read that when the blend door hits the stops it causes the amperage to rise to the actuator motor which the computer senses & turns off power to the actuator . This doesn't seem to be the case as the actuator turns a certain amount & stops when disconnected from the blend door .
On newer models I have read that the actuator can be manually calibrated by going through a procedure with the ignition on & turning the knob . Is there a way to calibrate the actuator on the 2002 ?
Sorry for the long post & I'll appreciate any help . TIA

I'm not sure the knob clicks but if turned a little the actuator turns a little & stops .

You can manually re calibrate the climate controls. it can be found in the factory service manual here is the link. Index of /manuals/Jeep/KJ

WE SHOULD STICKY THIS. I have come on here so many times answering the same question and this has worked many times.
If you don't feel like reading through that, here's the process.
Turn temperature knob to the 12o clock position (between hot and cold)
Turn key to accessory (don't start) within 10 seconds of turning the key to the on position, follow these steps


a.From the 12 o'clock position, rotate the temperature select control knob counter-clockwise to the full cold position. Pause one second.

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b.Rotate the control knob clockwise to the full hot position. Pause one second.

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c.Rotate the control knob counter-clockwise to the full cold position. Pause one second.

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d.Rotate the control knob clockwise to the full hot position. Pause one second.

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e.Rotate the control knob counter-clockwise to the full cold position.

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4.Turn the ignition switch to the OFF position.


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I have 05 & 02 KJ's & downloaded manuals for both . 05 manual gives instructions for the procedure but 02 manual doesn't . I have also read that 02's doesn't have the necessary software to perform this procedure . I tried it & it didn't work . Something has to control how long power is supplied to the actuator motor depending on where the temperature control knob is set .

Logan Savage said:

I have 05 & 02 KJ's & downloaded manuals for both . 05 manual gives instructions for the procedure but 02 manual doesn't . I have also read that 02's doesn't have the necessary software to perform this procedure . I tried it & it didn't work . Something has to control how long power is supplied to the actuator motor depending on where the temperature control knob is set .

Click to expand...

Any luck? I have an 03 liberted limited and replaced blend door actuator but once it goes full hot, it won't go to cool unless I shut off the engine and start it up again.