2000 mercury grand marquis air conditioner and heat seem to be running at the same time and defroster will not work.

Asked by Oct 16, 2013 at 05:52 PM about the 2000 Mercury Grand Marquis LS

Question type: Maintenance & Repair

the air conditioner on my 2000 mercury grand marquis operates with the heater on also. therefore it doesn't cool very well. also the defroster does nt function.

1 Answer


You have a heater door problem in the dashboard sounds like the AC/Heat door is NOT closing al the way AND the Floor/Defrost Door is not switching either. Sometimes 'things' will fall down the defroster duct and screw up the doors. Disassembly required to clear them. If you are sure there is nothing down there then you may have a broken vacuum line in the engine compartment that feeds the dashboard that is broken. Check against the firewall in the engine compartment on the passenger side - there will be white / red / green plastic lines. There will be one going directly to the dashboard around the heater hose area ( you may also find a hose broken off a mushroom shaped thing at the firewall - It shuts the water going to the heater core) Everything is control by vacuum going to your dashboard control. If you here hissing at the dashboard control - the control its self is bad - Good Luck

Your Answer:

Mercury Grand Marquis Experts

  • #1
    Tracy Hooks
  • #2
  • #3
View All

Related Models For Sale

Used Lincoln Town Car
29 Great Deals out of 1,466 listings starting at $1,900
Used Ford Crown Victoria
737 listings starting at $3,000
Used Chevrolet Impala
375 Great Deals out of 25,638 listings starting at $950
Used Ford F-150
2,300 Great Deals out of 208,487 listings starting at $1,300
Used Chevrolet Tahoe
522 Great Deals out of 37,993 listings starting at $1,243
Used Ford Mustang
266 Great Deals out of 37,717 listings starting at $1,350
Used Honda Accord
574 Great Deals out of 103,381 listings starting at $950
Used Toyota Camry
761 Great Deals out of 72,913 listings starting at $1,000
Used Cadillac DeVille
1,270 listings starting at $2,300
Used Ford Taurus
194 Great Deals out of 15,823 listings starting at $600

Used Cars For Sale

2010 Mercury Grand Marquis LS For Sale
6 Great Deals out of 66 listings starting at $3,995
2009 Mercury Grand Marquis LS For Sale
55 listings starting at $2,977
2008 Mercury Grand Marquis LS For Sale
5 Great Deals out of 73 listings starting at $3,000

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.