Tank Heater Indicator Lights

[MILPD4]

Hello all,

I so appreciate the wisdom and guidance I receive from this forum. Have learned and been helped a lot!

My question is, what is the purpose of the red indicator lights on black and gray tank heater switches? Do they illuminate when heaters are properly functioning, or does it indicate a "trouble" state? Owners manual provided no guidance.

May seem like a silly question, but I just replaced defective heaters, my tanks are empty, it is 28 degrees outside and I don't want to put any fluid in, and have read they shouldn't be activated empty. I could turn them on to see if pads get warm but fear damage but that still doesn't confirm the intent of the indicator lights...

It is a 2009 Four Winds Dutchman Dorado. I added an image as an attachment, but if that didn't work they are basically rocker switches with a red lens at the top where on is labeled on the panel.

Thanks in advance for any feedback!!

[puppygeo]

The lights indicate the tank heaters are on or off. If they are lit red, power is running to the heating pads. Whether the pads are heating up or not is another question. I wouldn't hesitate turning them on briefly to see if they light up.