We have had 2 of these model trucks with the same issue. One was sold before we could finally figure out what the issue was and the other we are currently involved with. On both units neither fwd or rev contactor would pull in on its own. We have pos BV on one side and no Neg BV on the other side of the coil. We have had all the cards sent out for repair and no faults have been found. Battery is good. All rec's and SCR's have been pulled and tested, all test good. Seat, brake, throttle and directional inputs all good. Looking at the print it appears that the negative for the contactor coils is supplied out of the card. This is wjhat we are missing. We gotta think this is a common issue on these trucks. The only two we have in our territory and they bnoth have the same exact issue. If anyone has any ideas it would be greatly appreciated.