New LED's won't work...

[partingclouds]

None of the new bulbs work, and I'd appreciate your ideas to help me get them lit up. What am I missing here?

Thanks in advance.

[bad.wabbit]

Flip the wire leads... voltage may be reversed.

[boatpoker]

Originally Posted by bad.wabbit

Flip the wire leads... voltage may be reversed.

+1.
LED's are polarity sensitive.

[Jd1]

Next time spend a bit more money and buy quality lights. They will be polarity insensitive and will last longer as well. I can highly recommend Marine Beam (Marine Grade LED Lights for Your Boat | Marinebeam) for excellent product and good service (previous customer).

[bad.wabbit]

Partingclouds - Jd1 Is raining on your LED parade, but if the polarity is the issue, he does correctly point out that higher quality bulbs are polarity indifferent. The other problem could be a too large voltage drop. Both of these potential problems can easily be tested with a voltage meter.

[Jd1]

An issue that a lot of people do not understand is that an LED is a current based device rather than a light bulb which is a voltage based device. To get the most life out of an LED you drive it with a constant current. The better lights have the circuitry built in to do just that. The cheaper LED's have no such circuitry and are over driven if you run them at 16V with your alternator charging and under powered when your battery gets low. This makes a large difference in the quality of the light output and the life of the LED. It generally also means that the LED is polarity insensitive which is really nice when you just replaced your mast top mooring light.

[hafa]

While I agree that top-quality lights make a ton of sense for critical use (navigation, etc...) and difficult to access locations, I take a different approach to interior lighting:

12V LED bulbs of all types for interior use can be had now for $6 for a pack of 20. In over a year of use under all kinds of voltages and situations, including a dying house bank, these ultra-cheap units have worked just fine. We Keep a spare pack on hand and if one fails, we take it out and stick in another. With over 30 lights in the interior of our boat, less=more.

[ValiantV]

Originally Posted by hafa

While I agree that top-quality lights make a ton of sense for critical use (navigation, etc...) and difficult to access locations, I take a different approach to interior lighting:

12V LED bulbs of all types for interior use can be had now for $6 for a pack of 20. In over a year of use under all kinds of voltages and situations, including a dying house bank, these ultra-cheap units have worked just fine. We Keep a spare pack on hand and if one fails, we take it out and stick in another. With over 30 lights in the interior of our boat, less=more.

Hey Hafa:
What LED bulbs are you using and where did you get them for so cheap?

We would like to replace all of our interior RV-grade light fixtures soon, but some LED lights to replace the bayonet-base automotive bulbs would be a good stop gap measure til we find some nice new fixtures.

[boatpoker]

I posted this article on my website about 8 yrs. ago. I've since sold that boat but know the current owner and these lights are still going strong. Last year I did the exact same thing on DIRT FREE.
CHEAP LED LIGHTS FOR YOUR BOAT

[Wallaby]

In addition to polarity, also beware of automotive-style bulbs which are usually negatively grounded to the car frame through the body of the bulb. Some bulbs will have two terminals on the bottom, which would appear to fit into a boat fitting, but do not. They are intended for two distinct circuits, for example parking/brake lights. Note that some boat light fittings have two wires and take bulbs with two terminals--hence the confusion.

I made five trips up my mast before I realized my anchor light was in this category. I was trying to install a low-cost high-output led light. BTW, I also carry a spare anchor light, just in case el-cheapo bulb breaks. So far, it works great.

[boeing1]

not much info on what type of led lights and how you connected them, agree recheck that you have correct polarity + _ connections,
I also second Marinebean for lights

[foufou]

Another consideration with LED lights is that failure of incandescent bulbs is corrosion of the sockets. An LED bulb in an old socket could have the same problem. Not saying this the case with the OP's problem but something to consider. A new LED fixture has no socket

[01kiwijohn]

Yep, Light Emitting DIODES means current only flows in ONE direction. If none work, check the polarity of the whole system.

[evm1024]

As noted you can use resistors to limit the current to the LED or you can use a constant current source to set the LED's current.

The resistor is not sensitive to voltage polarity so there is no need to put in the parts to make the LED polarity insensitive.

The constant current source is voltage senisitive so it must have the parts to prevent reverse voltages from reaching (and blowing up) the constant current source.

The parts that do this are 4 diodes in a bridge circuit.

The overall current draw of a LED is low (compared to an halogen bulb for example) so the voltage drop over the bridge (and power dissapation) is not really a problem. But it is there.

[PuttingDoctor]

As an aside for those who care.... if you have shorepower make certain you have connected the ground to the 12v bus not the shore power bus. Ask me how I know...