Question about 2006 Mercury Grand Marquis

1 Answer

2006 Merc GM, air flow out the defrost only problem.

2006 Mercury Grand Marquis
Regardless of my EATC output setting (floor, vent, AC, defrost, defrost/floor), everything works fine at idle and in park. Or at 2000 RPM's in park.

When in drive, when I accelerate or am putting any torque to the tires, my air changes direction and comes out the defrost. If I'm coasting (off the gas), the air flow switches back to where it's supposed to go.

The temperature works fine as I get cold when I'm supposed to and hot when I'm supposed to. My only issue is the direction of the air.

I'll more than likely take it to a shop in the spring (before I need AC when running) unless someone can pinpoint my issue and it's something I can fix.

Posted by on


1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.


    An expert that has over 500 points.

  • Expert
  • 316 Answers

Sounds like a vacuum problem. Check vacuum lines. Maybe hooked up wrong.

Posted on Oct 04, 2009

Testimonial: "IT ended up being the actuator/flap in the HVAC system that directed the air. My entire dash had to come out to replace the $15 part... $700 worth of labor and 2 return visits to deal with missed electrical connection to my daylight sensor and a vacuum leak that caused it to stall when put into reverse."


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

I have no control over the ac/heater blower motor. EATC replaced no effect

Have you replaced the blower motor speed control resistor located next to the blower motor? If no that may be the problem.

Feb 16, 2017 | Mercury Cars & Trucks

1 Answer

2007 merc grand marquis heater air comes out all of the vents and very little out of the defrost vents

Check to make sure the engine vacuum is getting to the heater/ac control. Bad vacuum hose or leak. Many vehicles use engine vacuum to move heater doors and controls. When the vacuum is absent, it usually defaults to air blowing out the AC vents.

Feb 01, 2014 | 2007 Mercury Grand Marquis GS Sedan

1 Answer

Air flow changes by itself from panel to defrost to floor vent. my vehicle is a 2006 merc. grand marquis

the vaccumm motors that actuate the mode doors are vaccumm driven.
if at idle all is ok then under accelleration mode doors change then there is a vaccumm leak in the system. look for a steel can (coffee Can) under the hood. trace the vacumm lines from there.

Jul 27, 2010 | 1993 Mercury Grand Marquis

1 Answer

2000 mercury grand marquis HVAC air distribution problem. Air comes out defrost vents regardless of control settings.

there is a vacuum motor that controls direction for air flow. when there is a vacuum leak, the control door defaults to the defrost vent. the motor, vacuum lines and directional control knob must be inspected. most of the time i have found that there is a vacuum line broken. purchasing a repair manual will help locate and discribe the system.

May 24, 2010 | 2000 Mercury Grand Marquis

1 Answer

No air coming out air vents whats my problem i hae a 99 merc ls

If you have the electronic automatic climate control, it's likely that the rubber O-rings inside the vacuum solenoids in the EATC unit are leaking. Usually you'll get cold air only out the defrost vents or floor with this problem.

If you are mechanically oriented, you can fix it yourself. I repaired the EATC unit in my 2004 Mercury Marauder in about three hours.

Complete instructions, including photographs and the part numbers for new O-rings and the dielectric grease for reassembly can be found in the user forums at

This is a manufacturing issue with the EATC head unit, so if you get a new one, get a written warranty. A new EATC unit is around $600.00. The parts to do the work yourself are about $12.00.

Hope this helps!


Feb 21, 2010 | 1999 Mercury Grand Marquis

1 Answer

2006, mercury grand marquis with EATC issue while accelerating.

Hello Bryan,

You either have a horrendous vacuum leak... or a muffler or catalytic converter (collapsing) starting to block you exhaust system...

A decent exhaust shop with code readers ought to be able to tell...

You would most likely be tripping OBD (on board diagnostic)
codes around your fuel system, oxygen sensors... and getting poor power and mileage...

Certainly worth a look...

I was STRANDED twice: once by a muffler... and again 15 years later by a collapsed catalytic converter.

Tow truck time.

Good luck.

Oct 27, 2009 | 2006 Mercury Grand Marquis

1 Answer

2005 Merc. Grand Marquis a/c full blower does not work. a/c goes through defrost vents and/or floor vents. Direct a/c vents go on, but kick off and switch to defrost vents, etc. Someone said it was the...

it not a motor its a module and you have look behind the radio in the dash and find it the dirrection section is not working for the area you dont get air

Sep 11, 2009 | 2005 Mercury Grand Marquis

2 Answers

2006 Mercury Grand Marquis AC

unless vacuum hose under dash is loose i doubt will be the blend door assembly expensive to fix

Apr 03, 2009 | 2006 Mercury Grand Marquis

Not finding what you are looking for?
2006 Mercury Grand Marquis Logo

490 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mercury Experts


Level 3 Expert

76649 Answers


Level 3 Expert

5537 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22219 Answers

Are you a Mercury Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides