No water to Whirlpool ice maker

I know there are other posts on this topic but I wanted to start a fresh thread. It is a Whirlpool side by side. The model number must be on the back of the unit because I can’t find it anywhere else. It has the water and ice dispencer on the left door. The ice maker will not fill with water but the water dispencer does work. When I open the door the red light blinks twice then pauses. When I push the flap in the light stays on solid. I’m thinking a bad water valve, but before I pull this thing out I want to be sure of what to check and how to check it. Thanks in advance, Terry.