Help with old Meade Newtonian Telescope Clock Drive

I am working with a local childrens science museum to set up their
telescope for Astronomy Day. They have an older (how old I can't
tell) Meade 8" Newtonian with what appears to be the original mount
and clock drive. The telescope was donated to them and they have no
operator manual. I had a few minutes yesterday to check the optics
(probably needs some alignment, but appears generally O.K.) and listen
for the motor to run (I heard it) when plugged in (No ON/OFF switch!).

My question concerns using the clock drive. I could find no way to
engage/dis-engage the clock drive. Is this common on older Meade
clock drives? Are they always engaged? Sorry I don't have any
further info on the model or description of the drive.

Thanks in advance.

Daniel Cervantes