I realized when performing the engine tests that when the cowl is installed over the engine and fuel tank, it would be difficult to tell if the fuel tank was full.
The easiest method is to pump in the fuel and wait for it to overflow out of the vent line. However, in an effort to reduce the amount of mess on the underside of fuselage I decided to purchase a fuel level indicator from RAM.
The product is advertised to be installed with the sensor at the bottom of the tank and therefor the lamp would turn on when the fuel level is getting low. The lamp would be placed in a visible location on the plane and therefor indicate the need for a swift landing before running out of fuel.
In my case the sensor leads where placed in the top of the tank to indicate when the fuel level reaches full.
As a result the lamp is on when the tank is empty and turns off when the tank is full. I decided to not tie in the power to the battery controlling all the flight systems to minimize the chances of an electrical failure and battery drain. As the sensor is only needed during tank filling the external battery connection makes sense.
The indicator lamp is visible through the front scale air intake in order to preserve the scale appearance.