Typical U-Joint noise. Makes noise in reverse but not in drive. Check both front and rear U-joints of the drive shaft. If one is bad replace both. You do not want to go through R&R of the drive shaft twice.
Bad shock mount? Loose exhaust system?
go to markviii.org. they have a answer for almost anything with the lincoln mark viii
There could be a problem in the steering linkage but most likely, the power steering pump is bad or low in fluid
Where to find the horn relay fuse for a 93 Lincoln Mark VIII
Not unless you try to change the whole front end of the car.
What is the question?
What's the question?