The drain cycle suddenly stopped but wash cycle worked fine. I stepped through handy manual cycles as shown in maintenance guide pamphlet. The drain relay closure was audible but the motor would not start.
I measured resistance of motor's drain winding and it was fine. The motor moved freely in both directions without any resistance so there were no obstacles in pump. I learned that many dishwashers run the motor in one direction to wash and opposite direction to drain. I felt something was wrong with the circuit board so removed it for close inspection.
By twisting tabs, you can carefully unfold the dual circuit board. There is a reversing relay, looks like SPDT, to control wash vs. drain. Upon careful inspection, I noticed one of the relay terminals had a cold solder joint and it caused some carbon at the terminal. A quick ohmmeter check verified the open connection, but you must have sharp probes because the circuit board has a protective film, fairly hard to penetrate. I re-soldered the bad connection, re-assembled all wiring and the dishwasher drained perfectly.
Problem solved. I saved the money needed for a new machine, plus the labor for installation !
I measured resistance of motor's drain winding and it was fine. The motor moved freely in both directions without any resistance so there were no obstacles in pump. I learned that many dishwashers run the motor in one direction to wash and opposite direction to drain. I felt something was wrong with the circuit board so removed it for close inspection.
By twisting tabs, you can carefully unfold the dual circuit board. There is a reversing relay, looks like SPDT, to control wash vs. drain. Upon careful inspection, I noticed one of the relay terminals had a cold solder joint and it caused some carbon at the terminal. A quick ohmmeter check verified the open connection, but you must have sharp probes because the circuit board has a protective film, fairly hard to penetrate. I re-soldered the bad connection, re-assembled all wiring and the dishwasher drained perfectly.
Problem solved. I saved the money needed for a new machine, plus the labor for installation !
