Replacing cabin light to LED - but don't work

[rsn48]

Thought I'd throw this Jeff Cote short video (2 minutes +) on why swapping out incandescent bulbs with LED bulbs may not always work - and the solution.

https://www.youtube.com/watch?v=LL56N5SRTSM

[janice142]

I had a friend pick up a new LED for a light fixture in my galley. I was so excited to upgrade. This was a dozen years ago... my first foray into the world of LED. And the dang light was yellow. Seriously, dim and yellow. Thank goodness I didn't get on the phone to complain about this supposedly "amazing LED" that was dimmer than a candle!

Yes, it was a polarity problem. I swapped the bulb around and it worked perfectly. Lesson learned.

Edit to add: my light was wired properly. There were two ways to inset the bulb. I did it the wrong way first.

[Comodave]

Well there is a 50/50 chance of getting it right or wrong. Of the two my luck is usually wrong…

[porman]

I think I posted this once on the Camano forum. I replaced the six cabin light bulbs with LED's and none of them worked. I removed a housing and saw a white wire going to a white wire and a black wire going to a black wire. My voltmeter showed the positive wire going to the bulb base and the negative wire going to the center. I had to swap wires around on all six lights.

[wkearney99]

Also be aware that if you've got dimmers on the circuit you may have to replace them AND do some re-wiring. LEDs do not dim like incandescents.

[PJHoffnet]

Originally Posted by Comodave

Well there is a 50/50 chance of getting it right or wrong. Of the two my luck is usually wrong…

Back in my NAVY days we called that the Fifty, Fifty, Ninety Rule. If there is a fifty percent chance of doing something the right way, and a fifty percent chance of doing something the wrong way, you'll do it the wrong ninety percent of the time.

[pjtemplin]

Originally Posted by PJHoffnet

Back in my NAVY days we called that the Fifty, Fifty, Ninety Rule. If there is a fifty percent chance of doing something the right way, and a fifty percent chance of doing something the wrong way, you'll do it the wrong ninety percent of the time.

Same when trying to insert the bloody USB thingy into the computer, right?

[utclmjmper]

Sounds like your trying to inform the world about what it already knows..>>>Dan

[Mischief Managed]

All the lights in the front third of my boat had reverse polarity. I know the mistake was made in a junction box/bus bar somewhere in the path between the breaker that serves those lights and the light fixtures, but I could not find it and ended up just fixing the problem at each fixture. I have only 5 non-LED bulbs in my whole boat now, the stern running light, the red and green running lights, and two odd sized bulbs in the cabin. The difference in power used is amazing.

[CaptTom]

Wait, someone thought it was necessary to create a video to explain that polarity can be reversed with incandescent but not with LED lights?

[wkearney99]

Originally Posted by CaptTom

Wait, someone thought it was necessary to create a video to explain that polarity can be reversed with incandescent but not with LED lights?

Sure, because most folks probably don't understand how incandescents actually worked, and how LEDs are entirely different. With incandescent you're just heating up a wire (or gas) until it glows, so it doesn't really matter how the power is applied, polarity-wise. Diodes depend on voltage polarity. LEDs have to regulate the power to effectively excite the diode into emitting light (to greatly over-simplify). Thus they need a reliable starting point of +/- voltage to function. Sloppy wiring for incandescents won't work.