I had a very similar problem a few months ago. My van would move a few feet then stop. I rang Powertouch, the chap was really helpfull. He kept saying it was my batery ,which I knew was fully charged. He then suggested I check the terminals on top of control box. I checked, they were all loose, mover fitted by local dealer, I tightened these , and no more problems. Be carefull not to over tighten the terminals, as you could snap them off. They are the brass coloured 8mm nuts which need tightening
------------- It's not what you take when you leave this world behind, it's what you leave behind when you're gone
I'm with Davewk on the Auto Powrtouch. It is just too dammed slow to engage and disengage.
My 2 previous MMs were of the manual variety and I would go back to these in a shot.
Our problem with the Powrtouch was one of the motors disengaging and as it ran back it overrun and got stuck, so when we arrived at the next site, that motor refused to engage. Ofcourse on both these occasions I couldn't find the T-bar to release it and had to manhandle the van onto the pitch.
Like Dave, I bought the Auto because of ill health but last season found myself lying on pitches trying to release the dammed MM more often than not.