Welcome to the forums.
First off, you have to give this board some time. Most replys come slowly.
The wipers may be the motor, or those relays. The way to check is just get a couple of wires and run them off your battery or a spare battery. On the side of the relay it should have a pin out that shows the location of the coil. You will see the common and normally open and closed contacts illustrated as well. Put power directly on the coil, pay attention to polarity! These are dc relays and may blow if connected backwards.
If the coil pulls in, you will here some kind of clicking as you touch the positive wire with the negative connected. If you dont here this noise and you are sure you are connecting it right, the relay is bad. If you do here this noise, get a ohm meter and make sure the contacts are opening and closing according to the drawing.
My blazer had some trouble starting when I got it also. I changed the fuel filter and havent had any problem since.
If you want more information or need specifcs on the relay testing e-mail me and I will do what I can to send you in the right direction.
JoulesWinfield@direcway.com
Also I have the Chilton manual for the blazer so I may be able to get some more information for you there.
Good luck
Joules.