The most common cause of Maytag Neptune Washer Keeps Shutting Off is a motor control board failure. The motor control board (MCB) on the Neptune is situated on the right side near the floor pan. On the stand alone models (non stacker) you can remove the door and front panel and take a look at the MCB. If you start up the machine and it shuts off within a few seconds that usually indicates the MCB has failed.
Since there is high voltage on board (170 VDC) components can actually rupture when they fail. Typically, the ten amp fuse will blow or it may zap a copper trace off of the board. If you inspect your MCB but don't see anything burnt on your MCB I would check the connectors on both the MCB and the machine control board which is located in the upper console section. It can help to unplug each connector and re install it to clean the connector pins/contacts. You should also have a special diagnostic sheet with a wiring diagram and other help information.
If you discover that your Neptunes' MCB has failed you can visit www.washerbearings.com/parts to order replacement parts other than tub bearings and seal.
Older Neptune's will need the motor conversion kit which includes a new MCB, motor and wiring harness and this is because Maytag had redesigned the motor drive system due to reliability issues on the older machines.
I hope this helped you. Leave any questions or comments below.
Jeff Hartman