Liamrose Having some trouble trying to find out what this blue thing is has a fitting for a hose and to connectors for wires but isn’t connected?
Angus242164 An '86 or later 240 seemingly. I haven't come across that part before, it may not be original, it looks to be a vacuum or boost switch.
Max Can you see a part number and type it into DuckDuckGo or Google?In the search type somepink like "9983258 Volvo " and see what it displays.