JCB 1110 2010 year, sometimes it will quit moving, but hydraulics will still work.

[nothingbutdarts]

As the title says, this JCB will stop moving or they will work fine for a while, but hydraulics still operate. Not mine, trying to help a friend get it working. he has check all electrical connections, fuses and relays and found nothing bad. I couldn't find a JCB section to ask in so I asked here.
Appreciate any thoughts!

 

[foton]

I would GUESS that it has a open circuit in the drive controls so it is not activating the drive section.

 

[nothingbutdarts]

Thanks much!