It would greatly assist if you said on what appliance
My caravan has a red light for room heater a red light to mains water heater a red light that shows when tap on the fresh water pump is on and if it stays on indicates empty water barrel. The omnial directional arial unit has ted light when switched on.
So out of all those which is yours.
bobuk
October 2017
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix camping equipment.