Possible key cylinder is bad, you have the wrong key, you have a very worn key are the first things that come to mind. Try another key. Try to pull clockwise or counter clockwise on the steering wheel and turning the key at the same time.
5300lbs.
Yes, a person can get a diagram of the PCV valve location in a 1989-1999 Mercury Grand Marquis. This diagram would be located in the maintenance books found in auto part stores.
left side of dash
( 20 U.S. gallons )
at the junk yard
According to my Chilton's Auto Repair manual : For a 1989 Mercury Grand Marquis : With engine oil filter change : Both the 5.0 / 302 and the 5.8 / 351 take ( 5.0 U.S. quarts )
its on the passenger side front near the front tire
I have a 1996 Grand Marquis. If one of the brake lights goes out the signal on that side flashes faster. I would check the brake/tail lamps.
It is part of the power steering pump assembly.
Follow the Youtube instructions.
If you don't see it under the hood, then look under the car just in front of the rear wheel.
it is either you have a shor in your wiring or you have a loose connectoin or you need a new relay