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jeffwhite's avatar
jeffwhite
Explorer
Nov 09, 2015

Help with Basic 12v troubleshooting, lights

I need some basic troubleshooting help. I have a set of sidewall lights by the bed (12V) on the same circuit as my Water Heater. Fuse keeps blowing, so I found the culprit, kinda. When I disconnect one of the 2 sidewall lights by the bed, bingo, all's good. The remaining light and the Water Heater work fine. As soon as I wire in the other light, fuse blows. Defective light, or defective wiring on that side? Should I measure across the open wires (on the problem light)and look for 12V? Measure the lamp itself?? jeff

10 Replies

  • jeffwhite's avatar
    jeffwhite
    Explorer
    Nov 09, 2015
    Chris Bryant wrote:
    A lot of wall sconce fixtures use a 1076 bulb, which has dual contacts on the base- hot and ground, rather than the standard single, ground through the base type. The wrong bulb will result in a short.

    MrWizard wrote:
    sounds like a short to ground, at the light fixture
    defective fixture, wrong bulb ?
    is the bad fixture in a bedroom slide ? if so could be a pinched or worn wire

    enblethen wrote:
    Check the lamp configuration. It could have the wrong lamp and is shorting out the circuit. Look into the socket, check to see if it has a single or double pin. Lamp should be the same configuration.


    Ding, ding, ding,ding..winner winner chicken dinner. Plugging a single pole bulb into a double pole fixture, ridiculous......Never even considered it. Thanks all. Gonna check out that "nuts and bolts, simpleton" troubleshooting link MexicoWanderer, thanks. jeff
  • Chris_Bryant's avatar
    Chris_Bryant
    Explorer II
    Nov 09, 2015
    A lot of wall sconce fixtures use a 1076 bulb, which has dual contacts on the base- hot and ground, rather than the standard single, ground through the base type. The wrong bulb will result in a short.
  • schlep1967's avatar
    schlep1967
    Nomad
    Nov 09, 2015
    I had a ceiling light that was acting like that. When we started taking it apart to troubleshoot we found the "extra" wire in the back was being pinched between a metal plate and the back of the light. We slide some heat shrink over it and solved the problem.
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Nov 09, 2015
    Without a doubt the best way to troubleshoot is to learn how to do it. The best way to learn to troubleshoot is the EASY WAY. A book written by a professional who knows how to teach the novice without trying to impress him with egotistical E=MC2 formulas. Such a manual is FREE FREE FREE and safe from cookies, ads, and garbage.


    http://kb-kbh.dk/shipslib/el_ombord/12volthandbook.pdf
  • MrWizard's avatar
    MrWizard
    Moderator
    Nov 09, 2015
    sounds like a short to ground, at the light fixture
    defective fixture, wrong bulb ?
    is the bad fixture in a bedroom slide ? if so could be a pinched or worn wire
  • Iraqvet05's avatar
    Iraqvet05
    Explorer
    Nov 09, 2015
    That does not sound like a switch problem to me but a switch is easy to diagnose with a multimeter. Tracing the wires maybe a challenge but one could have a grounding short. You swapping the good light into the space where the bad light was and see if that works or test resistance in both lights while they are unhooked for comparison.
  • enblethen's avatar
    enblethen
    Nomad
    Nov 09, 2015
    Check the lamp configuration. It could have the wrong lamp and is shorting out the circuit. Look into the socket, check to see if it has a single or double pin. Lamp should be the same configuration.
  • newman_fulltime's avatar
    newman_fulltime
    Explorer II
    Nov 09, 2015
    Sounds like a bad switch get a new switch from a big box store bet it fixes the problem

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