window wiper motor not working

1999 monte carlo z34 have replaced wiper motor twice still not working right. will not move blades expect about 2" and only on high speed, all I get is aloud click all the time, any ideas ?

You probably need a new wiper transmission assembly. It's the rods that run from the motor itself to each of the wiper arm shafts. GM part# 22127643.

only the motor is hooked up nothing else,

If only the wiper motor is connected, how is it moving the wiper arms?

with just the wiper motor hooked up the motor will not operate expect on high speed, also sounds like the wiper pump is on, all the arms are free ,they will move by hand,

The wiper switch is part of the multifunction lever. Does the pulse / low speed circuit have power when in low speed range?

try tightening the bolts on them, they could just be loose

Found out what it was, didn't buy one from the dealer as they wanted 375 so bought one from parts store for 95. Only thing it didn't come with the cover, returned 3 of them got my money back and then went to wrecking yard, brought it home pluged into electr. ports and it worked . so it was the control module on the motor itself.
thanx guys for giving me your opoions