Solved.
I replaced the resistors on the PCB. But I was wondering what caused the burning of it. So I measured the resistance on the wiring and from B+ and B- to ground.
It turned out I had B- lying to ground somewhere. That was quite a search. I found two shortcuts:
1. Some mechanic put a new turn signal on the forklift and that was grounded. Removed that. But I still measured chassis to ground.
2. The cable loom was stuck behind the valve block. The wire from the accelerator to the direction switch was grounded over there.
After that tested the forklift and everything was fine.
Powerlifter and Max, You've been a great help!
Frits.
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