Cessna 150 Part - What is its purpose

Discussion in 'Maintenance Bay' started by Skymac, Dec 8, 2016.

  1. Skymac

    Skymac Filing Flight Plan

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    Appears to be some sort of relay. It is under the panel on the right side of the plane. [​IMG]
     
  2. Skymac

    Skymac Filing Flight Plan

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    Appears to be some sort of relay. It is under the panel on the right side of the plane. I had posted this in another section then realized it wasn't the right tech area. As seen in the picture it appears as if it's been hot or shorted. The airplane is having a charging issue. Everything works great for about 30 minutes then begins a discharge... it has a new voltage regulator installed the alternator seems to be OK and resetting the alternator field does nothing.[​IMG]
     
  3. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

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    Definitely a relay. Is it just dangling from the wires? By the way, it's only rated at 3A, so I'd be really suspicious if it's driving more than that. I'd start by looking at any added equipment over what came from the factory.

    I'm not sure that's your problem however. Anything that could cause a system with a functioning alternator to register a discharge is going to be very HOT to touch while doing so.

    Two things to check on your problem:
    1. Is the alternator actually putting out when it exhibits this problem? If the plane doesn't have a voltmeter, you can stick one in the cigar lighter or some other convenient point.

    2. Check to see if some load isn't engaging (starter solenoids or landing lights are high drain items....).
     
    Last edited: Dec 8, 2016
  4. Checkout_my_Six

    Checkout_my_Six Final Approach

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    Is it connected to a hobbs meter....clock?
     
  5. hotprops

    hotprops Line Up and Wait PoA Supporter

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    unplug it with master off turn on master and see what does not work.
     
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  6. Tom-D

    Tom-D Taxi to Parking

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    Got a part number??

    Do you have a switch that is marked " radio 1" and "radio 2"
     
  7. Tom-D

    Tom-D Taxi to Parking

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    Most of these are hard wired.
    To me it looks like the re-lay that flip/flops the radios in the later production aircraft.
     
  8. Dan Thomas

    Dan Thomas En-Route

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    It's been added after production, maybe when radios were changed. It might be the mike relay. Hit the PTT button and see if that thing clicks.

    It's not part of the alternator or regulator system.
     
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  9. DFH65

    DFH65 Cleared for Takeoff

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    It's the turn signal relay. :)
     
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  10. wilkersk

    wilkersk Line Up and Wait

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    Since it's only rated for 3 amps, my guess is that it's a lighting relay. Perhaps it controls the light circuit on some internally lighted instruments and is energized by the nav-light switch.
     
  11. Capt. Geoffrey Thorpe

    Capt. Geoffrey Thorpe Final Approach PoA Supporter

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    The purpose of the part is to cost you a lot of money for troubleshooting when it goes bad.
     
  12. BigBadLou

    BigBadLou En-Route

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    All seriousness aside, this is the flux capacitor. Don't remove it, that won't fly. (pun sure as heck intended :D )
    (why the double post, btw?)
     
  13. hotprops

    hotprops Line Up and Wait PoA Supporter

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    if not hardwired do as stated above.most relays are plug and play
     
  14. Skymac

    Skymac Filing Flight Plan

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    Ha... yea, I was posting from Tapatalk and I thought I was in the right section. I'll check the voltage and see what we come up with. I'll tracing the wires back as well. They are just 20 gauge wire so there can't be that much draw on them, wiring is in great shape, it just appears to be smoked hazed inside the plastic, foggy. It very well could be a push to talk relay.
     
  15. Everskyward

    Everskyward Administrator Management Council Member PoA Supporter

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    The two threads are now merged into this one.
     
  16. weirdjim

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    Whatever its purpose, don't bring it to me for annual without insulating those bare terminals I see on the bottom. And how can a relay overheat unless it somehow has a full unfused +12 on one terminal and one of those other terminals hits airframe. Even then, the breaker should pop.

    I'll take liberties wiring an airplane, but this ain't one of them.

    Jim
     
  17. Skymac

    Skymac Filing Flight Plan

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    Not exactly sure where you see the bare terminal? It has a wire attached to every one of them. I've ironically been in 2 separate 172's before where the landing light switch had a come apart and no breaker ever tripped. These planes are getting old and the breakers fail causing the smoke to roll. I replace them in my aircraft, it's cheap insurance. This one though isn't mine.
     
  18. weirdjim

    weirdjim En-Route

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    Just to the left of the green/red stripe wire on the bottom of the relay -- next to the black tiewrap.

    It isn't at all unusual to see a cloudy plastic on a relay that has been in service for a dozen years or so, especially if it has been around any hydrocarbon fumes at all ... like what you might expect out of a cabin heat system run from a muffler shroud.

    Jim
    [​IMG]
     
  19. flyingbrit

    flyingbrit Filing Flight Plan

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    The relay appears to be just hanging from the wiring harness and not supported in any other way. I can't believe that Cessna or any conscientious mechanic would do this. Probably unrelated to the alternator problem anyway.
     
  20. Unit74

    Unit74 En-Route

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    Isn't that the bowling pin company- AMF? Do you have a lane or two in the back for those long haul flights?
     
  21. Checkout_my_Six

    Checkout_my_Six Final Approach

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    Zactly....blinkers. :confused:
     
  22. GlennAB1

    GlennAB1 En-Route

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    Hazard flashers.
     
  23. GlennAB1

    GlennAB1 En-Route

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    Or a blinking beacon... tis the season.
     
  24. denverpilot

    denverpilot Taxi to Parking

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    Hey, they made all the exhaust duct fans and closures for all the Minuteman silos... :)
     
  25. weilke

    weilke Touchdown! Greaser! PoA Supporter

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    AMF makes bowling balls, and motorcycles.
     
  26. denverpilot

    denverpilot Taxi to Parking

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    Used to make motorcycles, you mean. They sold that rather lucrative division off... :)
     
  27. weilke

    weilke Touchdown! Greaser! PoA Supporter

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    When the 150 was built they were making motorcycles, pretzel bending machines and nuclear reactors
     
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  28. denverpilot

    denverpilot Taxi to Parking

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    Ahh how the mighty have fallen... almost like bowling pins falling over, eh? :)
     
  29. Unit74

    Unit74 En-Route

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    Well.....rerack those mofos.
     
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  30. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

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    AMF had an odd strategy of buying up businesses they knew nothing about and were unrelated to what they were doing. More often than not, that didn't work out. It didn't take more than a four years after H-D was bought out that a hostile takeover got what was left of AMF and started busting out and selling all the component companies.

    The company that made the relay, Potter Brumfield got bought out by Swiss electronics giant Tyco (now called TE Connectivity).
     
  31. nrpetersen

    nrpetersen Pre-takeoff checklist

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    You might want to see if that relay clicks when the radio Push-To-Talk button is pressed. Jim W has probably done that more than a few times tho maybe not hanging free.
     
  32. Checkout_my_Six

    Checkout_my_Six Final Approach

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    So it's really a train company.....:eek:
     
  33. Jarhead

    Jarhead Filing Flight Plan

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    Turn on the strobes and see if you hear anything from it.
     
  34. Skymac

    Skymac Filing Flight Plan

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    Charging issue ended up being a field wire broken inside of the insulation and making contact on occasion. The box, is a relay for the radios. The wire took forever to run down. Didn't look damaged but sure enough was.
     
  35. mulligan

    mulligan Cleared for Takeoff

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    I believe it is a pre-wire harness for an AOA indicator
     
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