I checked on three different batteries, replaced the contacts of contactors (main and pump) for new motor insulation when measuring 500v: field about 2GΩ; rotor about 5MΩ that is very good. Curtis? Right here is something I do not agree. 1) I plug the batteries, starts to heat up PTC resistor, with Curtis on the main contactor out -24V, after entering the codes C28 error occurs. 2) Disconnect the A2 cable (-M) Curtis-motor drive, plug in the battery, enter the code, the truck passes the self-test, all functions operate outside the ride (cable disconnected) after connecting cable A2 to -M carriage ride begins and so on until the re-disconnection batteries.

First check if battery is OK at full charge (density and cell voltage), welded contacs in main or pump contactors, check motor isulation or defect in curtis controller.

Regards.