These current sensors monitor navigation light bulb current draw; navigation lights can be 12VDC (5, 10 or 25 watts) or 24 VDC (10 or 25 watts).

Each current sensor is wired to a navigation light and to a corresponding indicator on a switch or circuit breaker panel.

When the navigation light is switched on and lighted, the indicator illuminates.

When the navigation light bulb burns out, the indicator flashes on and off to alert the crew.



The QuickTime movie at the left shows a representative motoring situation, in which the bow (bicolor) navigation light bulb has burned out.

You may have to click once or twice on the movie to initiate flashing.



Many marine circuit breaker panels may be fitted with navlight INDICATORS and current sensors that match vessel navigation lights.

A single circuit breaker may control more than one navigation light as with this example, wherein the "running lights" breaker controls bow (bicolor) light and sternlight.

However, to properly detect and indicate bulb failures, one current sensor and one indicator must be provided for each navigation light.



Current sensors are designed to mount on negative bus bars, 1/2 inch wide with 8-32 tapped holes on 3/4 inch centers, the same spacing as standard circuit breakers.

This mounting also serves as the electrical connection to the negative bus bar.



This rear view of the above panel illustrates ease of wiring.

From each circuit breaker that controls navigation light(s), short jumper(s) (18 AWG) connect to corresponding current sensor(s).

Indicator positive and negative leads also connect to each current sensor; these wires are physically supported by the jumper.

The negative return lead of each navigation light connects to its corresponding current sensor.


These current sensors offer the following:

Compatibility with most recreational marine navigation lights:

12 volts DC: 5, 10 or 25 watt bulbs
24 volts DC: 10 or 25 watt bulbs

Compatibility with navlight INDICATORS

Very low battery drain:

Sensor draws less than 4 milliamperes (0.004 amperes) at 12 VDC.
Sensor draws less than 8 milliamperes (0.008 amperes) at 24 VDC.

Equivalent resistance in navigation light circuit less than 15 milliohms (0.015 ohms).

Quality marine materials:

Terminals, bracket and fasteners: Stainless steel

Enclosure, potting compound and printed circuit board flammability rating: UL 94V-0

Easy installation & wiring:

Current sensors mount to negative bus bar, having 8-32 tapped holes located 1/4 inch from edge and on 3/4 inch centers. Such bus bars are standard on many circuit breaker panels.

Fasteners are Phillips head SEMS (machine screws with captured lockwashers), directly accessible from rear of panel.

Navigation light negative return connection to current sensor uses same size 8-32 SEMS, normally used for direct connection to negative bus bar.

To order current sensors, please use our order page:


Current sensors will work with LED navigation lights that draw at least 250 milliamps. If your navigation lights employ 2-way switches (e.g. tricolor-anchor) and/or common negative return wiring, please address questions to: