It needs more pressure maybe. What color pressure restrictor is in the wall? Your suppose to time and count the revolutions on the wheels to determine which flow restrictor or whether to not use any on your auxiliary pump.

Have you cleaned the screen in the wall fitting?

I don't have a screen in the wall fitting. Not sure where to look for the pressure restrictor. Is it the blue disk inside the wall fitting?

I replaced the back up valve, bc that was just trickling water.

But the wheels aren't turning on their own when I turn the unit upside down in the water. Are they supposed to move on their own or only are turning when they glide along the pool surface propelled by the water intake?

There should be a screen inside of a glass jug on the fitting that goes into the wall. The blue disk is the flow restrictor. You are suppose to get a certain number of turns, I think 32 or so per minute if I recall. If you are getting too many, you go to the red disk. If you are not getting enough, you take the blue disk out. Are you sure your additional pump for the cleaner as well as your main pump are both on when you check this?

yes, barco, both pumps were on. The wheels were not revolving AT ALL independently when i turned it upside down in the water. They all do turn together if I spin them manually tho.

I definitely dont have a screen, and I don't know what you mean by a glass jug.

I just dropped it off at my local pool shop for the owner to look at. The worker said that if it was a broken belt or something, the wheels would not turn together when spun manually, so I have no idea what the problem is. I didn't try taking anything out. I think the blue disk is attached behind the wall fitting, I cant remember.