My Yale forklift has an issue with forward drive, and a few controls. Unit will always move in reverse. When going forward, contractors pull in, and I hear a winning noise(normal sound when driving) but will not travel. If I use the side shift, tilt, or turn the wheel about 20+ deg. it will move forward. I need to put some type of load into the controls for it to drive forward. Also sometimes the tilt, lift, side shift controls are just dead. If I keep jumping between controls it will then start working...Reverse is fine. 24V battery. Voltage is holding under load. any ideas of where to look?