Heated seats Fuse blows

[poorpeet]

Found I had heated seats today. They dont work so I started looking around. The plug on the drivers seat was connected but the passenger side one wasn't. got out the hand book & found out which fuse looked after them. When I checked it it was blown. I disconnected the drivers seat made sure the ignition was off & popped a new 30 amp fuse in. It blew after a second or two! Any ideas? Everything else is working.
I don't understand why it blows with the ignition off.
I'd have thought they draw too many amps not to be the switched side of the ignition.

[tonto]

Strange, I have also just discovered that I have heated seats !
I don't think mine come on unless the ignition is on. I can also hear a click under the dashboard (relay I presume). I can only think that the wiring is either connected up wrong (ie to a live feed) or there is a short.