Soap dispenser will not open during cycle

Could be the timer, could be in the wiring or could be in the release itself. Some openers allow a little bit of electricity to flow through the metal release latch, this makes the band, bent like a "C", to expand and it releases the door latch. You will need to do a little more sleuthing for this by removing the DW front and observing the latch action on the dispenser.