Hello, I recently purchased a 2015 S60 and while the rear defroster light comes on automatically at low temps, the back window never defrosts (no lines appear where the elements are) and the light never goes off (unless manually turned off). I checked the rear window heater fuse in the cargo area and it’s fine. The wire assembly back there appears fine. During my searches for a fix I came across one on another forum where the member said there was a relay (RMA3) in the circuit, but I’m not finding that relay on any diagrams I’ve found. Does anyone know if there actually is a relay and in which fuse/relay box it’s in? Thanks

 

It seems that the issue with the rear defroster in your 2015 Volvo S60 might be related to the fault relay. While the specific relay RMA2 is not commonly documented, it is worth checking the relay related to the rear defroster.
The fuse box in the cargo area is a good place to start, as it houses the relevant fuses and relays for the rear defroster. You may also want to check the fuse box in the engine compartment for any related fuses or relays.