calling au fan speed controller gurus

[08ESE]

So i just put a new motorolla transister onto my speed controller to find that the fan still blows when the car is off.

only difference is now its flat out and i cant slow it down when the car is going.

when you look at the inside of it, there are the two metal ribbons soldered onto the legs of the motorolla transistor and a third one, that looks like a ground / earth.

should this earth to the body of the unit?? or go onto the screw that goes through the transistor, which would insulate it?

also, are these controllers available new or reco anywhere?

thanks