Replacing a Hymer / Fiat Ducato Heater Resistor

2008 Hymer B544 based on a Fiat Ducato chassis. Heater and Air Con only work on max speed setting (4) all other speeds are dead 1,2 & 3. Usual cause is a burned out resistor but they are hard to find if you don&know where to look. If you do know where to look then it&a 5 minute job. It took me lots of digging to find out how to do it so I hope this short video helps the next person. Really all you need is a 5.5mm Hex socket (or small wrench/spanner) and the replacement part (About £10 , $12 on Ebay). I reckon this could save you a bit of money, time and energy rather than taking it into a workshop.