Washer trips ground fault breaker, but only after the sump fills with water. Switched to another GFI with the same results. Starting fresh with no water in the washer, and the breaker reset, the washer will fill with water, the motor runs ok, and the drain pump will empty the sump. At some point in the normal wash cycle shortly after startup, the breaker will trip. With the washer laying on it's side, I've made resistance checks to ground on all components that may come in contact with water, including the motor windings. Checks were made on 1k and 10k ranges with no meter deflection at any test point. Next step is to elevate the washer, fill it with water, and run the resistance checks again. There are no obvious visual signs of leakage or corrosion on the underside of the washer.

Any help, suggestions, or advise would be appreciated.

It may appear that the gfi is tripping due to water fill, but it may be due to current surge due to heater kicking on. DW pumps draw 1 amp. The heater can draw 10 amps. Check the rating on the GFI breaker and be sure its over the installation recommendations from Whirlpool. Also, breakers will typically trip at progressively lower current levels as they age and the more times they trip. It may just be worn out.