Thanks Chrissian. I have now replaced the lower light unit which was LED. Not too hard, unclip the outer shell, unscrew the indicator unit and replace. Does not tell you that in the manual which as Gambit says involves taking the glass out - you do not need to do that which saves the heater element. Glad to hear that you have not had temp problems with the caravan - nice boat by the way! Trouble with me is that even if its not broken on a car, i will find something to fix - hence the oil cooler project.