Question about 2003 Mercury Grand Marquis

1 Answer

Climate Control - Heat and cool work fine. Air flow is directed to defrost /floor. No indication (Sound or sight) that the vacuum diaphrams are being activated. The display on the dash matches the button being pushedwhich makes me think that the Climate Control electrical is ok. Wanted to trace the vacuum line without pulling the dash. Is that possible? Read an answer on your web sight which is very similar to my problem, but don't know where to look for the gasket mentioned. Answer was by Guru

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  • Mercury Master
  • 11,056 Answers

Does your vehicle have manual or automatic climate control ? You system is stuck in floor an defrost mode ?

Climate Control - Heat and cool work fine.  Air - 03 mercury grand marquis hvac air flow .-13qahwfdndst2y1hypmr2cdq-4-0.gif Item Part Number Description 1 18A318 Vacuum control motor-floor/defrost door 2 - Defrost air flow 3 18A478 Floor/defrost door 4 18476 Heater core 5 19860 Evaporator core 6 19805 Blower motor 7 - Outside air inlet 8 19A813 Air inlet door 9 18A318 Vacuum control motor-air inlet door 10 - Recirculated air inlet 11 18B545 Temperature blend door 12 18A559 Panel door 13 - Panel air flow 14 18A318 Vacuum control motor-panel door 15 - Floor air flow 16 - Vacuum from the engine intake manifold 17 19A563 A/C vacuum check valve 18 19A566 Vacuum reservoir tank and bracket 19 19980 EATC control
Pull the control panel an check for vacuum

Item Part Number Description 1 White Air inlet door 2 Yellow Floor/defrost door 3 Red Floor door 4 Blue Panel door 5 Black Source vacuum 6 - Not used


VACUUM APPLICATIONS CHART-ELECTRONIC AUTOMATIC TEMPERATURE CONTROL Switch Port Vacuum Harness Hose Color Func- tion Manual Override Selector Buttons OFF MAX A/C NORM A/C VENT FLOOR FLOOR/ DEF DEF 1 White Air inlet 2 Yellow Floor/ panel (partial) 3 Red Full floor 4 Blue Panel 5 Black
Source

Posted on May 21, 2017

  • 2 more comments 
  • Jeff Armer May 21, 2017

    Incorrect/erratic direction of airflow from outlet — manual climate control
    No vacuum to the A/C control (19980).
    Function selector switch (19B888).
    Vacuum hose/kinked/pinched.
    Airflow door binding/stuck.
    Vacuum control motor (18A318).
    A/C vacuum check valve (19A563).
    A/C vacuum reservoir tank and bracket (19A566).
    Vacuum actuator arm not connected to the door crank.
    Heater control valve (18495) leaks vacuum.
    Go To Pinpoint Test G .

  • Jeff Armer May 21, 2017

    Control Assembly — Manual A/C
    Removal

    Remove the finish panel.
    Remove the screws.
    Remove the climate control head

    You don't need to remove the whole dash to check this out .
    Where do you live ? If in PA i'll come an help

  • Jeff Armer May 21, 2017

    To get to the vacuum motor for the defrost / floor mode control , Remove the LH lower dash insulator panel and disconnect the lamp. This is above drivers knees !Remove the two pin-type connectors and remove the fill panel. This is at the driver right leg . next Remove the screws. Disengage the vacuum line. Then there is a module that has to be taken out of the way . Remove the lighting module.
    Remove the screws.
    Disengage the clip.
    Remove the lighting module. Remove the screws and remove the bracket for the lighting module and the connectors from the module. You should be able to see the vacuum motor now. See if you can move it by hand .

  • Jeff Armer May 21, 2017

    This is set up that if there is no vacuum in the system air is directed to the defrost mode .Coming out the floor and defrost the way it is makes me think there is a problem the floor / defrost door , not a vacuum problem . That's just a guess , without checking ?

×

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Posted on Jan 02, 2017

SOURCE: AC Problem

Sounds like the blend door is stuck. Unfortunately the blend door is buried deep within the dash.

Posted on Aug 02, 2008

emissionwiz
  • 75066 Answers

SOURCE: climate control codes

I have checked every site that I can think of and run the question many times, unable to get the procedure, maybe a nice tech at the local dealer will help u out, if not I guess buying a service manual might be your only option. I am a retired Ford mechanic, I did almost all the AC work, I never found this problem was a control head issue, it was always the blend door electric motor, I think you can see it from the glove box if you remove the liner.

Posted on Sep 09, 2008

emissionwiz
  • 75066 Answers

SOURCE: Climate Control

Pull the AC control head out and check for vacuum at the back of the control, if there is no vacuum or very little then the plastic line is pinched where it comes through the firewall on the passenger side behind the kick panel, that is most often the spot it gets squashed. am sure it is allot less than $800 to fix, maybe $200.00

Posted on Sep 09, 2008

alicantecoli
  • 22095 Answers

SOURCE: 2000 Mercury Grand Marquis will only blow hot air when ac is on

needs re-gassing because one line should be hot (feed) and the return cold , This is a specialist job do not attempt to do it yourself because its extremely dangerous with very high pressures involved

Posted on Jun 21, 2009

  • 490 Answers

SOURCE: this car has the automatic temperature control system

The hot/cold switch is probably bad.you have a blend door box that opens to let the cold air in and closes to let the hot air in.From what you are saying this part is no responding to the switch movement.Make sure power is at the switch and power should go through the switch when put on cold air this moves the blend door.Some times the blend door goes bad and has to be replaced its under the dash on the right side.

Posted on Aug 10, 2009

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26392097-cvaukpwazi2vnl4fgradjhua-2-2.gif

Item Part Number Description 1 18A318 Vacuum Control Motor-, Panel/Defrost Door 2 18A478 Panel/Defrost Door (Full Vacuum Position) 3 - Defrost Air Flow 4 - Side Window Demister Air Flow 5 18B545 Temperature Blend Door (Full Heat Position) 6 19860 A/C Evaporator Core 7 19A813 Air Inlet Duct Door (Full Vacuum Position) 8 - Outside Air Inlet 9 18A318 Vacuum Control Motor-, Air Inlet Duct Door 10 - Recirculated Air Inlet 11 18527 Blower Motor 12 19A566 A/C Vacuum Reservoir Tank and Bracket 13 - Vacuum from the Engine Intake Manifold 14 19B888 A/C-Heater Function Selector Switch 15 - Vacuum to the 4x4 Hub Solenoids 16 18495 Water Diverter Valve (Full Vacuum Position) 17 18476 Heater Core 18 18A559 Floor/Panel Door (Full Vacuum Position) 19 - Floor Air Flow 20 18A318 Vacuum Control Motor-, Floor/Panel Door 21 - Panel Vent Air Flow

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Air Flow Control
Air flow control is accomplished in the following manner:
  • Primary control is through the function selector knob mounted on the A/C-heater function selector switch, which is part of the integrated control panel.
  • The function selector knob has the following positions: OFF, MAX A/C, A/C, PANEL, PANEL/FLOOR, FLOOR, FLOOR/DEFROST and DEFROST. The A/C-heater function selector switch combines a vacuum selector valve with an internal electrical switch.
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  • Each position of the function selector knob is detented for positive engagement.
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    • direct system airflow to the vehicle interior as determined by the remote climate control module or manual override.
    • The five-passenger seating configuration has an additional vacuum control motor mounted on the heater air plenum chamber to control airflow to the rear seat A/C register (19893).


vacuum control motor-i4bq0ig33y1522pr2d2rrkk3-2-0.gif

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possible climate control problem or the acctuator that opens the door for air flow from heater core. Check for a vaccum leak in the engine compartment or a bad diaphram on the acctuator, and even a bad cable from the control lever/knob.

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Heat does not come out passenger side of the car but comes out drivers side


There is a blend door problem.

---
prev.gif next.gif HEATING AND AIR CONDITIONING Refer to Section 1 for discharging and charging of the air conditioning system. The heating system provides heating, ventilation and defrosting for the windshield and side windows. The heater core is a heat exchanger supplied with coolant from the engine cooling system. Temperature is controlled by the temperature valve which moves an air door that directs air flow through the heater core for more heat or bypasses the heater core for less heat. Vacuum actuators control the mode doors which direct air flow to the outlet ducts. The mode selector on the control panel directs engine vacuum to the actuators. The position of the mode doors determines whether air flows from the floor, panel, defrost or panel and defrost ducts (bi-level mode).

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I have a mercury mountaineer 2003 V6. It has a problem of making sound repeated when I want to have heat turned on. No sound when the dashboard A.C/Heat stays at AC level, which is the zero? level. The...


When the engine is cold,check the coolant level.

Make sure it's on max.

===

A coolant system should be flush every two years.

===

If you did a coolant flush recently then air pocket can be the cause of the un-even heating problem.

The DIY method is to drive you car onto a ramp or a steep hill.

Iet the engine cool off and top off the coolant tank.

Set MAX heat + MAX fan

Let the engine ran for 20 minutes wih the cap off and the trap air will escape from the coolant reserve tank,

Check coolant level and top off coolant when the engine cools down.



A shop will charge $75+ for this but using an air operated excavate tool!

========

A car with over 90K miles may experience linkage problem to the heater control valve.

The heater control valve (near the firewall) may be stick over time.

Open the hood and move the heater to max and min. Back and forth.

Clean and lube the linkage with WD-40 to free the heater control valve.

If it's a vacuum type heater control valve then cash for leaky vac. hoses.


=======
Move the fan switch back and forth to re-new the electrical conductors.

Pass a vacuum over the control panel to prevent dust build up behind the console.

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