There where several things wrong with it. I finally got a master mechanic for Crown out to look at it and we tested all kinds of things. First the large diode was blown and letting current flow both ways. A the large resistor was bad and when we replaced it we found the bad diode and that half of the motherboard was bad. I thank everyone for helping me and writing back to fix this problem I just was hoping it wasn't as bad as it was.

Sounds like brake accumulator pressure. The beep/chime should go off when the pressure is reached (if it ever does).

It is permanent. From the moment I plug in power.

Sorry. I should have put: this forklift once turned on and I sit in seat will start a continuous beep sound. It will not go forward/backwards, or any lift/tilt controls.

I think thats your hour meter reading as the FC4000 uses the EV100 control system which doesn't go above code 200. FC4500 doesn't go above 300 and the new FC5200 doesn't go above 800.

The display should have a small spanner icon, is this lit when it says 978 as that would indicate a fault code. Is 978 shown on the display permanently or only when you key on/off?

What issues with the unit lead you to think you have an error code, is it functioning correctly?