It is true that in general capitals are used for shouting but sometimes people need to use capitals for a good reason, so if your one of those? then carry on,
Now then, blown air has been around since the late 70's and not changed at all, apart from the addition of mains electric as a heat source, that was introduced by Carver for the 95 season. So unless your van had it fitted after it was built? then you will have blown air with only gas as the heat source. If you do have electric, then this will be controlled by a switch on the wall with two grey push buttons and 5 yellow lights.
Assuming you have not, you will have a small matchbox sized dark brown or black box to control the 12 volt fan motor, this will have a numbered dial and a red switch with three positions, middle is 'off' and up will be fan, on this position the fan spins at whatever speed you set on the dial, down will be 'Auto' marked by an 'A', here the fan spins 'up' to the speed set on the dial, but actual speed is controlled by how much heat is being produced, this is the setting then for when used for heating.
All you have to do is light the fire, adjust it's control knob to a suitable heat output and set the maximum fan speed with switch on Auto, now sit back and enjoy!