1999 Dodge Caravan heating system

Unfortunately, features, (gimmicks, actually) such as this dual zone are all run by unreliable, complicated computers. Even the regular systems use computers instead of simple levers and cables. If the temperature never gets hot on the passenger side, a likely suspect is the motorized actuator for that door in the heater box. When the linkage is disconnected, move the door by hand to sure it's not blocked and the hinge isn't broken. If the door doesn't move freely, the AC system will have to be discharged so the heater box can be removed and disassembled. If the door does move freely, try a different actuator. If that doesn't solve the problem, suspect the computer module. Before removing the steering column and dash board, you might be able to access some of the actuators by opening the glove box, releasing the side tabs, and allowing it to drop out of the way.

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