That would depend on the exact model number of the machine and how it was designed. Either check the owner's manual or post the *complete* model number off the machine so we can see what design it is.
You can find tips for locating the model and serial number tag on your appliances in the 'Repair Parts' section of my site linked below.
** The dishes come out just as dirty as when went in. **
"Dirty" how? Still exactly the same food residue on them afterward as before, grit or food particles being redeposited on them??
Those symptoms could also be caused by the dishwasher not draining the dirty water out or not spraying the water properly during a wash.