All functions work except steering. S/N z45 001104 9/93. Tries to turn then quits.
controller issue maybe? Is it 2 wheel steer of 4 wheel steer? maybe they didn't have 4 wheel steer back in those days......just one dual-axis controller for drive and steer, right? That would be my best guess. You need to confirm there is power leaving the controller when steering.
Electrical more than likely
2 wheel steer. Electric is all functioning valve is operating
Hold Steer Switch left and check voltage on TB36 Hold Steer Switch left and check voltage on blue wire at Steer valve Remove both wires from left coil and check resistance across coil terminals (4 to 8 ohms is good) (zero or infinite, replace valve coil) If the coil is powered, and resistance is good, replace steer valve.