Gauge Components & Senders

About Gauge Components & Senders

Marine Senders

Boat sending units are designed to measure the amount of fluid in a tank, boat speed, temperature, and a variety of pressure-sensitive gauges. Senders can be replaced with parts from Defender Marine or full sender kits are also available for a variety of applications.

What is a Marine Sender?

Marine senders, or boat sending units, are designed as a simple measuring device that then relays (or sends) this measurement to a marine gauge.

How do you test a marine fuel sender?

Fuel senders can easily be tested with an ohms tester. A variety of fuel senders are available including level arm, swing arm and solid float, and conventional style float switch type senders; all can be tested by reading the ohms output.

Floatless marine senders measure for many different gauges.

Pitot kits measure a boat's speed while more technological speed sending units rely on GPS to garner a constant speed reading. Temperature sending units from Defender Marine measure up to 300 degrees and relay this back to temperature gauges in many applications. Pressure sensors measure essential pressures such as oil pressure in the engine. Newly designed floatless senders measure tank pressure versus fluid capacity.