@ethan_caumeJSZ3B wrote:
Just wondering if someone can explain how XREFs work in a relay/coil relationship, as they keep appearing as "?" and I don't know what their purpose is.
Those mean your XREFs locations are not found in the current session of the DWG file being open.
the XREF palette will list where those locations where last saved, perhaps you can use that to either reload them or go on the hunt for them in Windows File Manager.