Thank you elektrodrive
shall try
Hi Valeriy
Sounds like the truck is regen braking fiercely. Check the regen diode circuit in line with the contactor and also check the regen contactor.
If its twin drive, then there is a small contactor which sits on its own for motor lockout i think, if that contactor is not operating you can have it simulate the same problem, as that is what the problem with my truck was.