Hi there
I had a similar problem some time ago on a linde but not sure what the model was.
We found that the dead man switch had an internal microswitch which was faulty, if your truck has this microswitch on the dead man try bridging this out to begin with.
If that checks out ok check the throttle pedal voltages.
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.