So they only work on one speed ( full speed) & then if I do fluid, the wipers turn on as normal but stop in random spots... Also sometimes when I turn them on the make a really loud humming/vibration/bad noise.... What do I need to replace?

 

You have the wiper speed control switch on the turn signal lever? Twist the lever to pick a speed? If so, that's the first place i'd look. On my '93 Laredo that switch has about 8-10 positions, or 'clicks', each one a faster speed until it gets to full time running. (no delay)
It sounds like a bad switch to me, but if you have the click-click-click for each position, it could be bad wiring in the column.
Also, i'd check the actual wiper mechanism itself. Make sure it's not 'binding' or badly in need of grease.

edit: after i posted i re-read and since you said it made a humming noise, that could be the wiper motor or the motor speed control board.. Where does the humming noise sound like it's coming from?

 

From where the wiper arm connects to... I think maybe the wiper motors are bad??? Are there more than 1 motor???

 

One motor runs both arms. Sounds like bad motor or shot bushings or connection in the linkage. Remove the wiper arms and the cowl and check it out. Good luck and let us know how it goes!

 

Needs a new motor