Resistor for nav lights

b.gagnon

Master Chief Petty Officer
Joined
Apr 28, 2001
Messages
835
My boat has separate bow and stern nav light switches, and there is a resistor? that connects the two, that is broken in half. What does this do?
 

Boatin Bob

Lieutenant Commander
Joined
Sep 24, 2001
Messages
1,858
Re: Resistor for nav lights

Never heard of having 2 separate switches, are you sure it's a resistor and not a diode? Do the lights still work or what is the problem?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Resistor for nav lights

This is a simple diode, not a resistor. Radio Shack can fix you up for just a few cents. Even though you have two switches, they function as a single center OFF, up NAV, down ANCHOR switch that has three terminals. To make a long story short, you can't make a switch like that turn on the stern light only, or both the stern and bow lights at the same time. The diode prevents current from going to the bow light when the anchor position is selected. Simply connect the new diode between the terminals that feed the bow and stern lights. A diode allows current flow in one direction but not the other so proper orientation is required.
 

b.gagnon

Master Chief Petty Officer
Joined
Apr 28, 2001
Messages
835
Re: Resistor for nav lights

The lights do work..The diode is burnt up and cant see the color. What do I buy?
 

18rabbit

Captain
Joined
Nov 14, 2003
Messages
3,202
Re: Resistor for nav lights

If everything works as it is supposed to, discard the diode. It is possible a diode was needed at some time in the original configuation, but it is not always needed, depending on the light switch(es) used. Your system may have been updated, thus no need for the diode anymore.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Resistor for nav lights

If these are two simple on/off switches, there is no way to turn on the bow and stern lights with one switch, and just the stern light with the other without using a diode. The simple reason is that the hot lead from both lights goes to one switch. The hot lead from the stern light goes to the other switch. Remember that the stern light in this configuration is connected to both switches so when the stern light switch is flipped on, the bow light will also turn on since its connected to the other switch along with the stern light. The diode prevents prevents feeding that circuit. However, this whole thing is a moot point if everything is working properly and I doubt it is unless some other switches are used.
 

waterone1@aol.com

Lieutenant Junior Grade
Joined
Oct 10, 2004
Messages
1,235
Re: Resistor for nav lights

As upinsmoke said "I doubt it is working right". Time to check the lighting requirements for your size boat. You most likely have a stern/anchor light that has to perform "double duty"( by itself for anchor and with the red/green light for running).
 

cp

Petty Officer 1st Class
Joined
Feb 1, 2004
Messages
367
Re: Resistor for nav lights

b.gagnon - When you say you have "...separate bow and stern nav light switches." do you mean that one turns on only the red/green bow light and the other turns on only the all-around white light such that you have to turn both switches on to run with full nav lights? If yes, then just as 18rabbit says, you're good to go and don't need the diode. It's easy to wire the lights to work with two simple on-off switches under those operating conditions. Many are jumping to the conclusion that you have a 3-position on-off-on nav light switch like most of us have, and in that case a diode is needed. Since the lights work without the diode, sounds like you do have the two separate switches and don't need to replace the diode.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Resistor for nav lights

So why did someone install the diode? I don't think we are getting the full story.
 
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