Auto Air Conditioning & Heater Repair: 1998 lincoln towncar blows only hot air, motor actuator, lincoln towncar

Question
1998 lincoln towncar auto climate control problem system only puts out hot air, sounds like a door under the dash is opening and closing constantly it will stop when I set the temp. control to 75 degrees, but still only puts out hot air. When the car is turned off after warm up and re-started it puts out cold air for 10-15 seconds then max hot again no matter what the temperature setting is. Any ideas

Answer
Ray,

While I'm no Lincoln expert by far, the issue seems to be in the Blend Control portion of the A/C control system. While the Control Head (or whatever holds the climate control logic system) determines the blend door position, it uses a variety of sensors to determine position. If it's a feedback system, it actually monitors the position of the blend door by monitoring the voltage of positional sensors inside the motor (actuator, or whatever Lincoln calls them!). Regardless, this movement back and forth indicates either a failure of a driven component or the circuit to it(like the actuator), an inaccurate input to the logic (possibly due to a poor connection as well), or the Control Head itself. You can pretty much rule out a mechanical failure, like a broken door, just because of how it acts initially.

I'm not sure about the complexity of the system, but it sounds like a trip to the dealer is necessary, unless you have access to service information, and the diagnostic tools to properly troubleshoot this. Whatever the case, good luck!