We used the tank heaters a couple times last trip when the overnight temps went below freezing. Both times we used them we forgot to turn them off in the morning and they were on for a few extra days. I finally noticed that they were on when the converter fan was running because of the high current, the heaters run even if the temp is not below freezing. I decided to modify the tank heaters switch to be like the side view mirror heaters on the driver's door.
The switch can be removed from the cover plate and reversed so that down is "ON". I then painted the top of the switch with red finger nail polish so it is easily visible in the "ON" position. I used acetone to remove the "ON" and "OFF" markings on the switch that were upside-down and marked the lower position as "ON" with a Sharpie marker.
The switch now operates like the side mirror heaters switch and is easily noticed when "ON".
An easy and useful mod.
Bob A
