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Thread: master relay

  1. #1

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    Default master relay

    All, my master relay just gives me 9,4V output (13,2 input) - where's the rest gone? The 9,4 isn't enough for the radio & the rest: what can I do!?!

  2. #2
    Dave Holl's Avatar
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    Mar 2009
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    Default Re: master relay

    Looks to me the best advice is to throw it away! Seems that there is high resistance at the switch contacts causing a voltage drop. The other thing could be is the battery is on the way out and not able to sustain the hold in coil current but I would suggest that this is unlikely.
    Dave
    Dave Holl
    Building Kitfox MK7
    Rotax 912ULS

  3. #3
    Senior Member Dave S's Avatar
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    Default Re: master relay

    Hans,

    Sounds like Deja Vu all over again.....do a search on "Relay Failure"......I had a relatively new one puke.......queried the list; and, several folks responded.

    The thread includes a pretty good discussion including input provided by John Pitkin who had with some photos of various disassembled relays. After hearing John's explanation, I cut mine apart and found an out of tolerance manufacturing situation which was aggravated by the mounting position. I figured the manufacturing tolerance issue probably would not have manifest itself as soon if the Relay was in the recommended position...BTW - the only place you will find any reference to the mounting position is on the relay manufacturer's website and you have to look for it. If they were built correctly, mounting sideways should not bother them....mine were all uncertified/non-stc relays.

    Aside from a relay that is out of tolerance to begin with, wear and tear can take its toll on the contacts as Dave H has suggested resulting in a low conductivity situation.

    Low conductivity caused by internal slop or wear and tear can show up as low or absent voltage at the output end.

    Sincerely,

    Dave S
    Last edited by Dave S; 12-15-2012 at 03:50 PM.

  4. #4
    Senior Member jtpitkin06's Avatar
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    Default Re: master relay

    Here's the thread on the solenoid failure.

    http://www.teamkitfox.com/Forums/sho...start+solenoid

    John P

  5. #5

    Join Date
    Apr 2011
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    Jax, FL
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    4

    Default Re: master relay

    Gentlemen (and as always I use that term loosely , I have a similar problem with N2280J which is a 94 KITFOX IV. I am showing 11.8 volts on the MGL Velocity when all is working well, but I am frequently see 5.8V. I thought the contacts might be burned but maybe it is caused by the slop described below. I purchased an ECHLIN ST51 relay from NAPA that looks similar but it is not energizing. I see KITFOX has a master relay which I'll order later today. Thanks for the post. Regards, John

  6. #6
    Senior Member jmodguy's Avatar
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    744

    Default Re: master relay

    This is probably one place you do not want to go cheap. There are several manufacturers of contactors. Some are tested and some are not. I am using Sky-Tec battery relays in my system (dual batteries). These are good quality parts that are priced pretty reasonably.
    Remember you always get what you pay for. a $10 contactor will last about as long as you think it would... Probably made in china too.
    Jeff
    KF 5
    340KF

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