this is the auxillary heater.this is used to help the heating of the cabin.lots of smoke tends to give rise to a faulty heater inside the unit.lots of garages will tell you you need a new complete unit but this isn't true.you can replace the heater plug but it will require you to remove it from the vehicle.if you want more info on how to do this join www.fgoc.co.uk
This is the ford galaxy owners club and we have lots of how to guides for you to use to repair your own vehicles.
steve
April 2009