I agree. . even for those who are somewhat skilled the wiring diagrams let alone finding the connections in them. . .. are daunting. But checking and looking for loose connector pins or damaged wiring is a good a simple way to possibly find something.I’m less than useless but more than dangerous at wiring schematics. Guess I could disconnect/reconnect the plugs at the seat and see what happens. Other than that...
It may even be in the seat heating element itself that works manually when you are in the seat and makes a connection, but opens when cold and no one in the seat? Still very annoying.
If you know someone with a meter. . . and find the connectors under both seats. . . you could maybe compare readings in a cold condition and see it that reveals any open circuit?