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Tinstar's avatar
Tinstar
Explorer
Aug 08, 2016

8.7 volts incoming (MAYBE RESOLVED)

I came up with an unusual problem this morning. I've got 3 of the 2 light 12 volt fluorescent fixtures above my gally. Two of the three are burning, one is not (very dim). I'm thinking the ballast is bad in the one light that won't work. I did buy new bulbs and it did not correct the problem. The lights are F15T8. I opened them up and was thinking about putting led's in place of the fluorescent lights. I measured the voltage at the input line and am getting 8.7 volts at each of the 3 fixtures.

Is that right or if not, what would cause it? I thought there would be 12 volts at the input line. The batteries are fully charged, I am plugged in charging and I've checked voltage at other 12 volt outlets and am getting full power through them.

Any suggestions will be appreciated.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    I wired one of mine with LED's. and it got brighter (Very nice since it's the "Kitchen" light) .. A lot depends on the LED's.. I wish I could give you the link but I've misplaced the other coil of led's I got

    What I bought was a 5 Meter LED strip, It is sectional (joined) you can cut every 3rd LED if you like, I sliced and diced to fit, soldered on jumpers, and hooked it up.

    Well what do you know.. Found them
    Amazon Dot com
    .
  • Hey all, I followed your suggestions and after checking grounds and the feed wire @ 8.7 volts, I checked the wire at the switch. Apparently, I have a switch that its innards are not making good contact. I giggled it around and the voltage increased. The toggle switch feed wire is 13.4 volts (or there abouts) but the output side of the switch is reading 11.4 volts. It was lower than that when I first checked. Anyway, it's dropping a couple of volts inside the switch. I'm going to buy another switch since apparently there's corrosion in there. Also, the lights flicker pretty bad when I'm messing with this switch.

    I went ahead and wired the fixture with the bad ballast using leds. It's not quite as bright as the fluorescent but almost. I will probably go ahead and get a strip that is little brighter and change all three.
  • "Tinstar"....take the measurement again, but use another ground like the frame near the lights or add a long wire to your meter and pick up a nearby ground. Just don't use the one in the light fixture. Monaco had issues with losing grounds and running undersized wiring. I had a couple of lights in my Diplomat where I had to run new grounds.

    Once you resolve the power issue, you'll probably be happier with an LED replacement. You want LED's in the 3400 warmth range to give you equivalent colored lighting to your fluorescents.
  • One of my floursent lights would only work intermittently. It turned out to be the ballast. It had brown spots where it had gotten too hot. Not sure why it worked sometimes and sometimes not. It is now an led and works all the timr
  • My first guess would be a bad ground. Can come lose at any time....driving down the interstate or anywhere
  • take the wire nuts off and re-measure. Suspect a bad ground or loose connector. Back track to one light each side of the low voltage till you found the 12+ volts again.
  • jhilley wrote:
    Are you measring the voltage ahead of the ballast at the switch?

    I'm measuring it at the wire nut that feeds the fixtures. I guess that's the same thing but not measuring anything inside the fixture.
  • Are you measring the voltage ahead of the ballast at the switch?