Ymh,
It is hard to tell in the pic, but I assume this valve controls the input to your pump...
If that is true, then one of the two inputs is shut off.. Most pumps only have a few inputs..
Skimmer or Main Drain
Skimmer or Vacuum port
Skimmer #1 or Skimmer #2
Questions for you...
Do you have a vacuum port in the side wall of your pool?
How many skimmers do you have?
Do you know if your main drain is connected into the bottom of your skimmer or is it plumbed back to your equipment pad.
Can you show us a couple of pics of you whole equipment pad..
Thanks,
Jim R.