A -10 code will come up on the display, sometime the arm thats attached to the steer pot jumps off and that can cause the issue aswell.

check the mast position sensor up front
when you turn the truck there is a steering sensor mounted on the pivot point that measures the position of the mast to tell the drive motors how to run according to mast position. If that sensor is not adjusted properly, not calibrated correctly or is bad when the truck goes into a turn the drive motors will not change direction or power properly and cause the truck to get in a bind and actually keep it from moving.
It allows the motors to react in the same manner like a 3 wheel sitdown truck works when you turn the steer wheel on it. Reducing the power to the inside motor and when in its fulcrum point actually reversing the inside motor in the turn. If this does not occur the truck just will not run correctly and do exactly what you are describing.

We changed the motion control valve with new cartridges and this fixed the problem, Perfect!

Thanks for all the help guys,

Jonathan

There is usually a motion control valve located up on the neck of the truck that prevents a violent movement of the front end in the event of an impact. The valve is usually a silver or black block with 2 cartridges on one side, and the steering line plumbed thru it.

You may investigate this valve as the way it sounds one of your cartridges could be bad.

Edward, thanks for your reply.

The operator feels the heat on there legs, as if the heat is
Coming from under the battery.

The truck drives forward and back, will steer right but not left.

We have noticed if you operate the tilt, side shift or up leavers at
The same time as steering left, it helps and will steer left, not easily but it does turn.

At the start of the fork lifts shift everything works fine, we only get this problem after about 40 minutes of operating.

Thanks again Edward,

Jonathan

Steering switch not hitting?
When you say "steer left it locks up and becomes nearly impossible to turn" are you saying the truck will not swing left or are you saying it swings but then will not drive?
When you say "truck also gets very hot whilst trying to steer", are you saying the operator feels heat, or is it in the control panel or under the battery?
My "instant w.a.g.": you may have a bad motor, most likely a connection to the power cable, and will be pulling the battery out to look. it may even run when in the air, but under a load starts to have an open.