2000 E825 - No power to motor

I bought (2) 2000 E825s at auction. One runs good. The other has no power to the motor. The 12 volt components work, headlights, tail lights, blinkers, & wiper all work. I installed a new potentiometer, blinker switch and ignition switch from GEM. The ignition switch was missing & the wires were stripped at the ends & appeared some one tried to “hot wire” it by connecting the bare wires. The 12 volt systems work whether the new key switch is on or off. There is 74 volts to the to the right pole of the 400a fuse & 74v to the left pole when I manually close the contactor. The contactor does not engage automatically. The Zivan charger works & it appears to charge the batteries. The charge status light works. The BDI has no display. The backup beeper does sound when the switch is in the reverse position. It does not have the printed wire board, it has a DC-DC converter.

Any suggestions to troubleshoot the lack of power to the motor would be sincerely appreciated.

Thanks
Bob

Hi. I read your post. Did you get any answers to your post I have the same exact problem everything works but no power to the motor. Please if have gotten some information

If a fuse is good it will have the same voltage on both sides, any conditions.
Do I misundetstand?