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

Mike Bonnell

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

Add photo

Related Questions

Search Mercury Grand Marquis Questions

Mercury Grand Marquis Experts

#1 Tracy Hooks
Tracy Hooks
Reputation 4,820
#2 kbro
Reputation 1,910
#3 Js08016
Reputation 1,440
View All

Related Models For Sale

Used Ford Crown Victoria"
11 Great Deals out of 1,633 listings starting at $1,950
Used Lincoln Town Car"
55 Great Deals out of 2,377 listings starting at $1,542
Used Chevrolet Impala"
948 Great Deals out of 35,753 listings starting at $700
Used Cadillac DeVille"
2,394 listings starting at $1,600
Used Ford F-150"
3,183 Great Deals out of 216,374 listings starting at $1,900
Used Honda Accord"
1,272 Great Deals out of 77,636 listings starting at $1,395
Used Ford Taurus"
358 Great Deals out of 23,065 listings starting at $1,400
Used Ford Mustang"
718 Great Deals out of 41,256 listings starting at $900
Used Chevrolet Tahoe"
1,056 Great Deals out of 36,219 listings starting at $1,700
Used Buick LeSabre"
15 Great Deals out of 2,572 listings starting at $1,950

Used Cars For Sale

2010 Mercury Grand Marquis LS For Sale
8 Great Deals out of 123 listings starting at $3,299
2009 Mercury Grand Marquis LS For Sale
4 Great Deals out of 113 listings starting at $2,995
2008 Mercury Grand Marquis LS For Sale
5 Great Deals out of 143 listings starting at $2,900