Interior Lights and Dimmer

The information provided is for a 2002 Duffy 18' Classic. Many systems and components are common across models and years.
It is up to you to determine if this information applies to your boat or not.

Dome Lights

The original parts are "Perko Surface Mount Dome Light - 5" O.D. (4" Lens) - Chrome Plated. Part #0300DP1CHR".

Companionway Lights

The original parts are "Perko 1044DP1WHT White Flush Marine Utility Light with Snap on Cover". Shoreline Marine makes a non-dimmable LED replacement (Part #SL91504), but it will not work with standard Duffy wiring which runs all interior lighting power through a dimmer.

Dimmer

The interior lighting has a common negative and a switched positive. Most dimmers will not work with this arrangement as they require isolating the negative side of the circuit going to the lamps. For this reason, you need a dimmer designed for RV or Marine purposes where a common ground is normal.

Imtra ILDIM-ROT10 Dimmer

Our boat has an Imtra ILDIM-ROT10 dimmer, which has a panel-mounted potentiometer wired to a dimmer box. This dimmer from PCA Electronics is advertised to work with the lamps on either the positive or negative side, so it should work (I have not tried it). I don't know the diameter of the panel hole, which you should note when ordering a replacement part.

Imtra ILDIM-ROT10 Dimmer

The power requirements for our dimmer are modest.

Light	Volts	Amps	Watts
Dome 1	12	0.94	11.28
Dome 2	12	0.94	11.28
Companionway 1	12	0.25	3.00
Companionway 2	12	0.25	3.00
		2.38	28.56

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