Have had this dishwasher for about 3 years. Now it runs for a few minutes then pops the 20 amp breaker. Pulled the DW, checked all connections, replaced the breaker and it still pops. Anything I can do or is it toast?

Is the DW on a dedicated circuit? If so, sounds like the motor is pulling too many AMPS. Check the screens under the main arms, sometimes the underneath reservoir loads up with unused detergent and could bind the motor shaft.

Yes, it is on a dedicated circuit. How do I check that underneath reservoir? The main arms turn freely. What else do I need to do to check there?

The arms spin free since they have to rotate. Pull the baskets out, Take off the center spray arm, some have a small screw, most snap on, look for a detent. Then remove the screen and see what's underneath. Water flows thriugh the pump and needs to have a means to circulate the water. Make sure it's clean under the screen. If everything is clean, look under the DW for a lint filled motor, that would do it also. Unfortunately, almost all of the motor/pumps are sealed and difficult to access.