1997 Lincoln Town Car Signature, 145,000 miles, 4.6.
Last summer I had my A/C recharged and checked, and it worked fine for 3 or 4 months, and then the A/C stopped working and it would only blow heat, which I am unable to regulate. It blows straight heat, I can adjust the fan speed, but not the actual temperature. When I press the vent, defrost, outside temp, buttons it will only blow heat.
Sometimes when my control unit is off, heat will still blow from the floor vents.
I had the AC checked and everything appeared fine, they recommended I replace the cycle switch, which I did. I eventually replaced the HVAC unit, which also did not fix the problem.
I have been told that my " blower is stuck open" but if that were the case, why does it not blow cold air when I turn the AC on?
Is that the correct diagnosis? Or what do you think it would most likely be?
It's probably the blend door actuator. We're having the same problem with our 98 Towncar. The part costs $46 from the Lincoln parts dealer. You can run a system check for a code 24 or 25 that will confirm that you need to replace the blend door actuator.
1) turn car on and stabilize temp; 2) press the " off" and " floor" button at the same time; 3) let go and immediately press " Auto" and release; 4) you will see the LED display doing a segment check for about 20 seconds; all segments wil display simultaneously if no codes are found; 5) press " defrost" to exist the self test.
We had a code 24 show up on ours indicating that the blend door actuator needed replacing. Ford came out with a service bulletin #TSB 98-6-3 concerning this matter.