2010 S80 Fan Relay Schematic

adamkhan · Post by **adamkhan** » 10 Aug 2019, 00:32

Hi, does anyone have a schematic or diagram of the Radiator Fan Relay Circuit? I replace my relay after it was stuck in the on position and drained my battery. I replaced it with the cheap $30 one off amazon and it was only turning the fan on very momentarily. The second one I installed worked great for 2 days then quit. I'd like to wire in heavy duty 5 blade 30 amp relays, 1 for each fan. Has anyone decoded or reverse engineered the circuit? There's only 3 wires coming into the relay; Positive, Negative & signal but it controls both fans independently. Some Magic happens inside!!

Post by **RickHaleParker** » 11 Aug 2019, 16:56

The 2010 S80 does not have a Cooling Fan Relay. It has a Cooling Fan Control Module. Which is located on the cooling fan. The third wire is a communication bus, the ECM sends commands down that buss to the Cooling Fan Control Module.