A motor like any load has to have power to run. It must be getting power to it from another source. Your job is to find that source.
Luckily my son works for a shop and has access to Mitchel so I got the diagrams for both 2 speed and intermittent.
Not sure which you have but it looks like based on the photo of the wiper control, you have intermittent.
Shown here:
http://s1371.photobucket.com/user/St...tml?sort=3&o=0
NOTE I think the drawing is mis labeled on the low line. It should be the orange wire NOT the grey wire. The grey wire is out to the pump. I feel the low line is the orange wire and this one is the one to focus on.
The motor is going to have a 5 pin connector going to it. One pin is ground. One other pin connects to the washer pump. One pin brings 12 volts directly from a fuse. This pin will be hot as soon as the key comes on. The last 2 remaining pins are hot only when the wiper switch is in either High only or on low or intermittent.
So if your wipers are running on low (when they should be off). Then the high speed switched wire is going to be off when your wipers are running all the time.
First question, when your wipers are running when they are not supposed to be, are they running at normal speed or hi speed?
With power off (battery disconnected if you have to), disconnect the connector at the wiper motor and confirm the ground wire is connected to ground. The black wire. Ohm it ground and confirm it gives you the same reading on the meter as when you short the leads together.
Now keep the connector off the wiper motor and reapply power (connect the battery if you have to).
Measure the voltage on the purple wire. It should be low or 0. Now for the problem child, the orange wire. Check it see if it has 12V.
I believe the orange wire will have 12 volts all the time. Let us know what you find and we will go from there.