How do you replace a 1993 plymouth grand voyage power steer pump

As the two systems are not connected in any way, I would call it an odd coincidence. The power steering is a hydraulic mechanical system that routs fluid pressure created by the power steering pump and signals are input from the steering shaft to the rack n pinion. And the wipers are electric mechanical that takes the power from the electric wiper motor controlled from the wiper switch to the wiper transmission which moves the wiper arms.

Could be bad power steering pump, no power steering fluid
Broken belt/s or other more serious problems.

Never brake fluid and nothing else goes in brake master cylinder.

Put power steering fluid or automatic transmission fluid (dextron)

I suggest you to replace the power steering rack. You can get Power Steering Rack for all Plymouth models at http://www.carsteering.com/steeringparts/Plymouth/Power_Steering_Rack.html

if you leave in Michigan you can get a used on at LKQ in Grand Rapids Mich Phone 616-877-3490 its self serve for around $25.00 if you do not leave give this website a try to find a good salvage yard near you www.junkyarddog.com wish you the best of luck Michigan Man.

check all the bearing in all of the acc. power steering pump water pump idler pully a/c compressor etc. if all good no nise and they spinn freely check the alinment of all the puilly mak so they all line on together. sometimes the power steering pully get worn inside the pump and allow it to move back and forth too much some play is normal. also the power steering pully trys to walk off the shaft and make the belt track off the other pullys .

check the 2 lines that go to power steering pump for leaks

you really don't want to do this job!
it's a hard one even with a hoist and the right tools

ck the belt, and the belt tensioner.

belt is cheap. power steering pump is cheap (find a good used one a salvage yard) power steering rack is a bit more expensive and more involved to replace. you really need to know what is bad. make sure the fluid is full first. any noises?