Cruisers & Sailing Forums (
-   Electrical: Batteries, Generators & Solar (
-   -   Navigation Lights Troubleshooting (

SV Second Wind 02-08-2016 06:39

Navigation Lights Troubleshooting
Hello All!

Finally got Second Wind, Cape Dory 28, back in the water for the season due to some much needed chain plate repairs! Last year nav lights were working fine, but now they are not turning on. Definitely an amateur when it comes to electrical work. How would you recommend I start tackling such an issue?

I'm assuming since the two lights are wired in parallel and both lights are not turning on, that it is likely an issue with the wiring vs both bulbs being burnt out.

Please see below for condition and tests conducted so far:

  • Both bow nav lights (red and green) are not turning on. Stern light is wired to the steaming lights so not a reliable source for pinpointing the issue (prior owner/yard wired it this way. I will fix this while I'm figuring out the bow light issue)
Tests so far:
  • Checked the fuse and it was in good condition, even tested with my multimeter.
What would be the most logical next steps? I have a multimeter to help tackle the problem.

I appreciate everyone's feedback!

Thank you!


a64pilot 02-08-2016 07:01

Re: Navigation Lights Troubleshooting
Take a bulb out and with the multimeter test if you have voltage in the lamp, then work backwards from there, or start at the other end and work forward.
Me I think I would start at the switch, I assume switch cause you said fuse.

On edit, check grounds if you find voltage and it still doesn't work, seems problems are often with a poor or missing ground.

jstevens 02-08-2016 07:22

Re: Navigation Lights Troubleshooting
You say you checked it with the multimeter, what did you find? As A64 recommended check voltage at the lamp contacts. Bow lights suffer a lot from corrosion. The multimeter may show 12+ VDC, but the corrosion could still prevent the bulb from lighting. Make sure your lights are not wired in series, in which case a burned out bulb will cause both lights to go out. That would be unusual, most bow lights are in parallel from a distribution point near the bow, but given what your PO did with the stern light, I wouldn't rule it out.


nigel1 02-08-2016 07:45

Re: Navigation Lights Troubleshooting
As a check for the bulbs.
Are they the same as the stern light?
Does the stern light work?
If yes, try the side light bulbs in the stern light fitting, that should rule out the bulbs.

As you said you are an amateur when it comes to electrics :), when you check the contacts in the side light bulb holder, make sure you have the multimeter set to measure volts DC, it probably has a setting for 20V DC which, so long as your boat is 12V, would be OK.

Check both the condition of the bulb holder contacts, and the ends of the wires going into the bulb holder. If the previous owner used non-tinned cable, it is likely that the cable ends will be corroded which would cause the bulbs to not light up.

Doodlebug 02-08-2016 12:09

Re: Navigation Lights Troubleshooting

Originally Posted by oivivio (Post 2180232)
How would you recommend I start tackling such an issue?

What would be the most logical next steps? I have a multimeter to help tackle the problem.


If you do not have a wiring diagram or a as-built try to find a diagram on the net that looks like what you have. As much as I love my VOM a simple test light and 30 feet 12 ga wires will find problems faster.

GordMay 03-08-2016 03:41

Re: Navigation Lights Troubleshooting
Greetings and welcome aboard the CF, Brad, & Doodlebug.

SV Second Wind 07-08-2016 14:47

Re: Navigation Lights Troubleshooting
Thank you everyone for the great advice!

I had a brief time back on the boat this weekend, but did not have a chance to do a full analysis of the circuit. I opened the electrical panel and found a birds nest of wires twisted, halfway soldered and insecurely wrapped with electrical tape. I'm thinking the issue may lie somewhere in here or corrosion mention from many of the posts. I will definitely investigate further this week and into the weekend.

Some how I was able to pin point the bow running lights connection to the pos+ running lights breaker along with the stern light. The stern light works so I will begin to investigate the wiring of the bow running lights.

Thanks everyone for the help. I'll let you know what I find!

All times are GMT -7. The time now is 09:39.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.