Product review (2 stars): Whirlpool 8558129 Dispenser Assembly for Dish Washer
I had to take the new and old dispenser apart and swap out the solenoid, as the electrical connections was on both solenoids were different.

Put it all back together and it works just fine, but would of liked to have used the new solenoid. I did save the new solenoid, just in case the old one goes bad and will splice the wires to make it work.

I should not of had to change out the solenoid, it should of been a like for like replacement.