This mod will let you use the full range of your heater control without having to continuously run the fan motor. This conserves the fan motor bearings and electrical draw, while allowing a temperature controlled, fresh air flow through the cabin. Air flow will naturally depend on vehicle speed, but is noticable at all speeds and equivalent to fan position #1 at about 65MPH. In this procedure you will disable one of the fan positions (I chose position #4, high speed, because I used it least) by removing the appropriate connector pin. Here's the procedure: 1. Remove the heater control, using the procedure in this section http://www.jeepkj.com/forums/viewtopic.php?t=1002&sid=79faa6e854d68b9c138b38948313dbfc 2. Gently remove the back side of the control unit, lifting it over the snap pins. pull the pin selector knob off. The pin lay-out is as follows: Connector pin assignments ('04 control shown) 3. To disengage the #4 fan position, gently pry the #6 pin off. #6 pin removed ('05 control shown) 4. replace the pin selector knob and snap the back cover back on. The pins on your control unit will now look something like this: 5. re-install the A/C heater control. Everything will now work as before, except the #4 fan position, which no longer exists. This is your new "vent" position. I have done this on both the '04 and '05 heater controls. The pin assignments are identical. A word of caution: Any A/C and/or defrost (which also employs the A/C) setting should have a continuous air flow across the heat exchanger for efficient use. For that reason, this newly created "vent" position would be appropriately used for heated and ambient air only.