Overview

The Hella Marine 958130691 is an incandescent DE3175-style festoon bulb for compact onboard fixtures that take a 31 mm lamp with SV8.5-8 end caps.

It runs on 12V and draws 10W, so it fits many small courtesy, cabin, and utility lights on boats that specify this bulb style. The light has the familiar warm tone you get from an incandescent filament.

Key features

• DE3175 / 3175 festoon format with SV8.5-8 end caps
• 31 mm overall length (about 1.22 in), for fixtures specified for 31 mm festoon lamps
• 12V, 10W incandescent bulb for standard 12V DC lighting circuits
• Fits spring-clip festoon holders, with no rewiring when replacing the same bulb type
• Keeps the incandescent look and dimming behavior where the fixture uses this bulb type

Compatibility and fit

Festoon bulbs are all about physical fit. Confirm your existing lamp is the 31 mm style and that your holder uses SV8.5-8 end caps. If your fixture calls for a different length (for example 36 mm or 42 mm) or a different base style, this one will not seat correctly.

Also verify system voltage. This is a 12V bulb and should not be installed on a 24V circuit.

Installation and replacement

Turn off the light circuit at the switch or breaker and let the old bulb cool before handling. Remove the lens, press the bulb gently toward one spring contact, and lift the opposite end out of the holder. When installing the new bulb, make sure it is centered and that both end caps are firmly captured so it cannot rattle loose under vibration.

On-board use notes

This bulb suits boat owners maintaining existing incandescent fixtures in cabins, companionways, lockers, and other small interior locations where the fixture is labeled for a 31 mm festoon lamp. It is also a sensible spare to keep onboard when multiple fixtures share the same bulb size.

Maintenance and care

Keep the contacts clean and free of green corrosion so the bulb does not run hot at the connection. If a light flickers underway, check for weak spring tension in the holder and for pitted contacts, then address the fixture before blaming the bulb.