How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Michael Your Own Question
Michael
Michael, Ford Senior Master Tech
Category: Mercury
Satisfied Customers: 275
Experience:  Ford Senior Master Tech with 14 yrs experience with Ford, Lincoln, and Mercury
15033637
Type Your Mercury Question Here...
Michael is online now
A new question is answered every 9 seconds

My 2006 Mercury Grand Marquis has auto climate control but

Resolved Question:

My 2006 Mercury Grand Marquis has auto climate control but is stuck on defrost/floor even if I try to override in manually it will not change.
Submitted: 8 years ago.
Category: Mercury
Expert:  Michael replied 8 years ago.
Customer when you press the buttons on the automatic climate control unit does it register that you have tried to change the setting or is the screen locked up?

 

Thank you,

Michael

Customer: replied 8 years ago.

It changes on the display but the airflow doesn't change thru the vents

 

Expert:  Michael replied 8 years ago.
Customer do you currently have access to the vehicle?

 

Thank you,

Michael

Customer: replied 8 years ago.

yes

 

Expert:  Michael replied 8 years ago.
Customer I'm going to walk you through a self test. Start the car and close the doors. Press the off and floor buttons together, then release them and press the auto button within two seconds. This will start the self test mode. If there is a problem detected you will get a two digit code. If nothing is detected all the lights will light up after the test. Try this and let me know what you find.

 

Thank you,

Michael

Customer: replied 8 years ago.

ok will do

 

Customer: replied 8 years ago.
I ran the test and all the lights lit up
Expert:  Michael replied 8 years ago.

When the air blows out of the dash, does it only blow from defrost?

 

Thank you,

Michael

Customer: replied 8 years ago.
that is correct, a little on the floor maybe but not enough to warm my feet
Expert:  Michael replied 8 years ago.
Customer there are two possibilities that I can come up with for your problem.

 

First is the source vacuum line to the climate control system. The air flow distribution control doors are moved by vacuum operated motors. If the vacuum line that goes to the climate control module has no vacuum on it the system defaults to defrost only.

 

Second is the climate control module itself. The vacuum distribution is handled by the climate control module (the module is the control panel you use to select the climate modes). If the part of the module that handles vacuum distribution fails you would lose control of the doors. The self test will not pickup vacuum issues, it only checks for electrical problems.

 

The first thing I'd check is the source vacuum line. If you look under the hood it is the line that goes through the firewall into the dash. Make sure there is vacuum on it. You can also look under the dash on the passenger's side of the car. The vacuum line should be visible from there. The source hose is usually white, but not always. If you have good vacuum into the car, try disconnecting the battery for five minutes to reset the climate control module.

 

If none of that helps you need a new climate control module. 90% of the time when I see the same symptoms you have it is caused by a source vacuum issue.

 

Hope this helps, if you have any further questions do not hesitate to ask.

Michael

Michael and 4 other Mercury Specialists are ready to help you