I'm having issues with the drive system on an F35. I get no movement when the accelerator is uses, except at full throttle, if I wait a few seconds I can hear audible steps (I think 4 total) and then I get full throttle. It is also dependent on the steering wheel being set to mostly straight ahead. I just found out there is an interlock between steering angle and the drive controller. I haven't looked at any of the steering electronics, but I did take apart the box connected to the accelerator pedal and didn't find anything out-of-the-ordinary inside. Can anyone guide me to next steps? I have found the diagnostic switch, but I'm not sure where error codes would read out. The Display on the steering column only displays a "D" I believe. I see no procedure for diagnostics on the panel below the seat. Any help much appreciated. Battery is a full charge. All hydraulics function normally and at expected speed. Forklift has worked for over a year without problem. This is a new issue, possibly correlated with the weather becoming damp.