Interior lighting head scratching

[chowdan]

Hey all,

I am in the process of redoing(more like continuing) the refit on my boat.

I can't seem to figure out why my fluoro light isn't working. I have been scratching my head for a while on this problem, so maybe someone else can chime in and explain/give an idea on whats going on.

In the galley I have a fluorescent light off center of the stove to illuminate the counter and stove. The volt meter is showing 13.5v on the wiring coming out. The fixture that I am trying to use here is a dual bulb t5 fixture(Looks like a thin-lite fixture). The fixture hooked up to a different spot works just fine, however, bringing it back to where it should be installed seems to act like its dead. If i hook up a led/halogen light, it fires up and works without any problem, but a fluoro fixture does not seem to want to work.

Any ideas or tips would be greatly appreciated!

[hellosailor]

Dan-
If you've got power coming up to the light, then there are two problems that any fluorescent light can still suffer. One or more of the bulbs can be bad, usually the telltale for that is blackening inside the ends of the tubes. The other problem is a bad starter (looks like a thumb-sized tin can) or ballast (often an electronics module these days. If any of those is bad the light won't light. It is also possible you've just got a bad contact, a bad bulb holder, a bad switch.
Unless it is an especially good fixture, it may be worth replacing it with an LED fixture that takes only 1/2 the power, instead of trying to troubleshoot it further.

[chowdan]

Originally Posted by hellosailor

Dan-
If you've got power coming up to the light, then there are two problems that any fluorescent light can still suffer. One or more of the bulbs can be bad, usually the telltale for that is blackening inside the ends of the tubes. The other problem is a bad starter (looks like a thumb-sized tin can) or ballast (often an electronics module these days. If any of those is bad the light won't light. It is also possible you've just got a bad contact, a bad bulb holder, a bad switch.
Unless it is an especially good fixture, it may be worth replacing it with an LED fixture that takes only 1/2 the power, instead of trying to troubleshoot it further.

I am planning on going all LED on the interior down the road.

The confusing part is that this fixture will work just fine when hooked to a different location. Just that this location it does not want to work.

Maybe I'll just have to go without for a few months until I get new fixtures :\

I am thinking about using these acegoo recessed fixtures(link here), but still unsure as it stands. I will be replacing all my over head lights with something more efficient, but since i'm hooked to shore power and my headliner is in need of replacing, I dont want to replace them just yet.

[hellosailor]

"The confusing part is that this fixture will work just fine when hooked to a different location. Just that this location it does not want to work. "
You just solved the problem. If it works elsewhere, IT WORKS. And the problem is that the power in that old location is not good. If you tested the power connections and saw "12" volts, it is still common that there's a corroded wire or bad connection, so you are seeing 12 volts under no load, but the higher resistance from a bad connection is not allowing enough power to run to the light fixture.
Check, or just replace, the wire pair from the breaker to the fixture, and it will work in that location again. You'll need to do that to keep the new lighting happy, so doing it now won't be wasted.

[SteveSails]

Check the polarity (+ -), don't assume the wire colors are correct, check with a meter. I have seen fixtures intended for RVs where black is hot(+) and white is negative(-).

[skipmac]

Originally Posted by hellosailor

"The confusing part is that this fixture will work just fine when hooked to a different location. Just that this location it does not want to work. "
You just solved the problem. If it works elsewhere, IT WORKS. And the problem is that the power in that old location is not good. If you tested the power connections and saw "12" volts, it is still common that there's a corroded wire or bad connection, so you are seeing 12 volts under no load, but the higher resistance from a bad connection is not allowing enough power to run to the light fixture.
Check, or just replace, the wire pair from the breaker to the fixture, and it will work in that location again. You'll need to do that to keep the new lighting happy, so doing it now won't be wasted.

This is the most likely issue, especially if the light used to work in the same location but doesn't work now. The fluorescent draws more power than the LED and I believe even more on the startup which would explain why the LED works but the fluorescent doesn't.

[NakedCity]

Ditto on Hellosailor

This is why I like using a test light to trace out wiring issues. One strand of a 28guage twisted wire can carry full voltage but not enough amperage to power anything. If you checked the wires at the fixture with a test light it would probably just very dimly power your test light indicating broken, corroded, or bad wiring connections.

[Mike Banks]

I used to have fluoro lights in my vessel. I used a choke coil with them. There is a trick to it though--one has to wire them so that the power is not in the choke all of the time but only fed into it when the light is switched on. I used to wonder why my batteries depleted so quickly--till I found a warm choke when the light was switched off.

I junked all of the flouro tubes and replaced them with pairs of LED lamps. Just as bright and far less power used, and could be individually switched to red for night use..

Caravan type fluoro lamps I would replace. They are a poor substitute for modern LED lamps.

[Dougtiff]

As already stated above, the problem is a corroded section or bad connection, that will show enough voltage, but enough load will disrupt current floe, i.e. the flouro bulb,however the LED does not pull enough current to stop the current .