Originally Posted by Mk4 Rick

Im also a plumber but also a car mechanic and hgv driver lol.Any way find a suitable place to mount your switch imo I would keep the relay if possible inside the car to keep the weather away from the relay.Use a 4 pin relay pin 30 accessory (FAN) pin 85 earth pin 87 perm live and 86 switchable ignition.and you should have it.Use a multi meter if not sure to find switchable ignition hope that helps