Was getting boil over on long city trips while sitting in city traffic, then I noticed that the electric cooling fan was not turning on. Pulling the QC connectors off the stat located on the radiator, and shorting them together resulted in a click of the relay, but no spin. Pulling the fan relay and jumpering the two pins in the socket with the large wires going to them resulted in the fan turning on. That can only mean that the relay was bad. I discovered that by removing the rubber sealant on the bottom of the relay by rubbing it off with my fingers, I could pop the cover and inspect the guts. The contacts are good, not burned, so closer examination yielded cracked solder joints that Volvo relays are known for. A quick fix with the soldering iron, and I save 20 bucks. Re-seal the base of the relay with silicone and you are done.