for me it has to be the one that the yellow arrow is pointing at on my granada, its not standard and I have no bloody idea what its for or what it does. its nice an springy when ya press it but it don't click or nothing, its wired right into the fuse box but thats about all i can say, lord only knows. nothing comes on or goes off, just pointless, but i leave it there cus else i will have a whole in the dash.