Could be a number of reasons. There may be blockage which prevents air from flowing over the fins of the condenser. There may be a blockage elsewhere in the AC system. It could be insufficient refrigerant.
You can try cleaning off your condenser (I would not recommend using a pressure washer for this, whatever you do - condenser fins are brittle and bend easily). If that doesn't rectify the problem, you'll need to take it into a shop and have a system performance test conducted.
The ( 2007 ) Mercury Grand Marquis has a ( 19 U.S. gallon tank )
( # 16 ) is a 20 amp fuse for the cigarette lighter and OBD II in a 2007 Mercury Grand Marquis ( in the fuse panel below and to the left of the steering wheel by the brake pedal )
According to the 2007 Mercury Grand Marquis Owner Guide : ( 19.0 U.S. gallons / 71.9 litres )
That car doesn't have a cabin filter.
The salvage value of a 2007 Mercury Grand Marquis varies greatly depending on your area and the actual condition. There are prices between $100 and $2500.
Usually on one of the Trunk Lift Rods.
Go to a Ford dealer parts department and request the part number and diagram of the part location. I did this for my 2004 Grand Marquis. It is located on the lower right center of the dash panel on the 2004 Grand Marquis. Try this link http://car.justanswer.com/uploads/Auto TechInSTL/2007-07-16_213138_sc2.gif.
No, you should use the correct parts to make sure it works reliably.
On a 2007 Mercury Grand marquis : The electric fuel pump is INSIDE the gas tank ( a picture I was looking at shows that the fuel tank is mounted vertically behind the rear seat and the fuel pump is mounted in the side of the tank that faces the rear seat , near the top of the tank )
Vacuum check valves are usually located close to the vacuum source.
cheap caliper compressor from auto parts store, 1 size fits all.
( 6 quarts / 5.7 liters ) with engine oil filter change , according to the Owner Guide