In theory one should always check the original (even photograph it) before dismantling - but the factory install of the heat seats - at least in my 2015 - involved copious duct tape meaning the cables had to be pulled BEFORE getting good access to the switches (unless you are cleverer than me and disconnect the feed and earth from under the dash 1st, and leave the switches in situ making sure the feeds for the seats come out with the gearbox cover). Probably could have been photographed if up on a lift!
I used a multimeter to try and ascertain the poles on the switches - and still got it wrong on reassembly. Not suffering from a cold bum I don't miss them but my occasional passenger likes them so at some point over the summer will have to do some dissasemby, reassembly, and fuse changing...