Thank you MEngr and crownie for your replies.

I'm a user, not a forklift tech, and while I have mechanical (Automotove) skills I do not have the service manuals or scanner for this. What I did do is check and clean all electrical connections, battery voltage is 25 at rest, drops to 23.5 when raising a 225 pound person until it shuts off after a few feet. So it seems as if voltage is OK.

However one interesting thing I just found is that when raising the platform smoke comes out of the left drive wheel motor where the power cables go into the motor housing. That cannot be good. Interestingly motor brushes are in spec, commutator looks OK and it does not smoke when driving and drives OK.

When the cart is stationary and the platform is raising I would think there would be no voltage at the wheel drive motor so why is it smoking then and not when it is powered up and driving? Time to call our dealer for a service call I think.....

I'll post again with what the ultimate problem/solution is in case it helps others.