DADS50 shows the correct location for the switch. There are several different kinds with different things on the paddle and colors. Some say AIR others HEAT and some DEF usually brown or black. Right next to it (to the right) under the dash is the correct location for the fairly rare fog light switch. I will post some more photos that illustrate placement and switches they are on my work computer. You can also see mounting details in some of the accessory manauals I know the 53 version shows it.
