Problems related to DCS connection

Valve site is OK but there is a problem at DCS site. I changed the fuse, opened the JB connection and tightened it again, but it still shows mega ohms. Air pressure. Body actuator is fine. Now can I change to other coil?

Do you have current in the loop? I’m assuming it is 4-20 mA. Take a resistance measurement for whatever coil you’re referring to. If it’s not open you can easily test it but applying rated voltage to the coil. Was a fuse blown? If so you have a wiring issue or valve full of water or shorted to ground. Do you have a process meter? Can you simulate a 4-20 mA into the DCS to narrow it down to a field issue? Double-checking the wiring, ohm it out. You should be able to simulate the loop to verify the cable is good to the DCS. Can you stroke test the valve with your process meter or by other means