One of the air bags probably has a leak.
You can't, the serpentine belt (or fan belt) on a grand marquis is equiped with a self tensioner, if your belt is making noise it either needs to be replaced or one of the pulleys on the cars may be loose and would need to be replaced.
If it is leaking it needs replacing. If you have no heat and the inlet heater hose is hot and the outlet is cool, it is stopped up and may need replacing, if it cannot be flushed out.
One of your door sensors needs to be replaced.
Most likely the ac belt is loose and needs to be tightened or replaced.
1988 Grand Marquis hubcaps have a lock on them. You'll need to buy it. The center panel (with the mercury logo) comes out and you'll see a little opening that is flower shaped. That needs to turn to release the hubcap from the lugnuts.
there is a awitch on the chassis rail that needs to be bled, or replaced either go to a mechanic or get a workshop manuel this switch is called hydraulic control unit (HCU)
Call for help. Fuel pump is INSIDE the fuel tank. The entire tank needs to be removed to get at the electric pump.
no they are not in the way at all but the air box intake needs to be removed to get to the left side spark plugs
Remove belt and check to see that it rotates freely and smoothly
Typical Ford wiper switch malfunction. The wiper switch needs to be replaced.
There is a spring loaded tensioner that is supposed to keep the serpentine tight. If it is loose, it needs to be replaced.
Its the blend door. It happened on my 98 Mercury Mountaineer. The motor shaft and the door have separated there is an easy fix look up blend door fix for 98 Mercury Mountaineer it just needs a small finishing nail and done