Freemasm

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About Freemasm

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  • Location
    Orlando, FL
  • Model
    M20C

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  1. Freemasm

    Burned output lug on alternator

    Going by memory here but I think some of the older Prestolite based units have an AC terminal about where (I think) your picture is indicating. If anything is connected there you're shorting straight to ground and would cause some of the issues you're shown/described. Yes, it's a long shot based on the mounting bracket shown. Can you tell us what nomenclature is stamped next to the lug?
  2. Freemasm

    Aircraft Switches for sale

    @Jorgypilot, email sent to listed email address. Thanks.
  3. I had to rebuild mine by bonding/riveting replacement “wings” on the sides. You could make one completely out of aluminum but as you can see with it removed, the back plane has a slight bend to accommodate the breaker bodies. Good luck. It seems it’s always the little stuff that gets you.
  4. Freemasm

    Gear limit switch locations

    Get a full gear rigging check. You're balancing over-center torque, actuator over-run, actuator life, and more. It's always important but switch removal and subsequent adjustment makes this critical. On another note, relays tend to stick more than switches. The next "failed" actuation you experience while testing, I'd lightly rap the relay(s) and observe.
  5. Freemasm

    Gear limit switch locations

    Don't know what that would be for. Starting vibratpr and gear contact current share a 10amp breaker in my schematics
  6. Freemasm

    1969 Dimmer Control Needed

    If your light control box is like the one pictured above, I'd absolutely go with the max pulse/maxdim. These are good products. If you have the box with integrated push-to-test and photocell dimming circuit, it will be more difficult to replace but do-able. There are two distinct lighting circuits separate from the PTT/annunciators and auto-dimming circuit. @SkyTrekker if your fuses are good, I'd guess your rheostat/switch is bad. Below is another thread where I was trying to help someone else. (One of) The original rheostat switch(es) was an Allen Bradley JS1N040P251MA. It can be a bit painful but they can be fixed.
  7. Freemasm

    Gear limit switch locations

    I wouldn't be able to advise from pictures. When you stare down the parallel wiring of the two relays, you'll probably understand. Took some time for me to trace everything down and subsequently label to get my head around it. That was a long time ago. At least the position switches are easy to test in place. One will be actuated from the current linkage position, the other can be actuated with your finger. Who knows. It will get figured out. edited to correct ASSS position. Looks like it is "reverse acting".
  8. Freemasm

    Gear limit switch locations

    If done correctly, you’ve isolated it to the up relay or the motor. I’ll see if I can make any more suggestions after I look at the schematic. Hopefully tomorrow. It is tricky. The relays are wired in parallel so that juice to one isolates the other and vice versatility. Don’t know that I could talk anyone through that. Would have to study the actual circuitry myself to hve a chance at making sense of it. ASSS seems high. A Vx climb won’t allow a retraction. Will have to look at what SM states, if anything. Changing is pretty easy. The limit switch screws in/out of the housing that holds the bellows.
  9. Freemasm

    Gear limit switch locations

    If you're new to circuits, I'd probably watch somebody the first few times to learn. If you don't have a multi-meter, I'd get one and some alligator clips. It can be an invaluable, cheap investment. A hobby type is better than one tended for home circuitry for this use IMO. Also get your aircraft's service manual for the circuit diagrams. Invaluable. I'm speaking for 69C circuitry but they should be the same. First off, leave the master off or better yet pull the battery terminal. The gear circuit has two circuits; one for "control" or contact, the other "relay" circuit powers the motor. Opening the gear breaker only gets one side; you're still exposed to a potential short. For testing for a closed switch/circuit (in this case), your testing for a very low resistance. This will work but most multimeters have a continuity setting with an audible alert. This is better for initial troubleshooting IMO. Find the screw terminals on the device and test there. A closed switch will read very low resistance/buzz in continuity check. Test both sides of the gear switch when properly placed. Test the Airspeed Safety Switch (ASSS) as mentioned before. I'd strongly recommend against the motor testing if you're new to this. I also wouldn't jumper/bypass the ASSS without the aircraft properly jacked. You're asking for potential, expensive trouble. As mentioned, if you're new to this, I'd probably get with someone who isn't. Nothing worse than costing yourself money.
  10. Freemasm

    Gear limit switch locations

    Landing gear switch is a three way switch. One side can go bad but that’s not the way you’d bet. Test for continuity across that switch. Then put the multi-meter across the airspeed safety switch. “Increase the airspeed” and you should be able to hear that limit switch close about 80 mph and see continuity across the switch at the same time; all without jacking the plane.
  11. Freemasm

    Gear limit switch locations

    Sorry. Didn’t see where he said three wire. That’s even easier to test because the field will get juiced from the main lead.
  12. Freemasm

    Gear limit switch locations

    Breaker doesn't make sense to me assuming your gear would lower but not raise. If you can measure continuity across the switches, relays and airspeed safety switch when properly actuated, it's got to be a motor issue. One direction tends to go intermittent/bad before the other does. Guessing your motor is a four wire Dukes 4196. The commutators on these (and others) will wear out. Not too hard to test in place if you know how to safely work with DC/isolate circuits. There should be knife splices on the four motor leads. Green = ground Yellow = field Red = contact for one direction Black = contact for other direction Take lots of pictures/do lots of labeling before you disconnect anything. There's enough going on, circuit wise, to make reconnection a PITA. There as a place that can overhaul/yellow tag these motors but they are getting rare. For that reason, I've had all three (gear, flap, fuel) overhauled in the last 18 months or so. George's Electrical Service (916-927-3386) in Sacramento, CA knows these motors well and will do a good job. Keep us informed. Good luck.
  13. Freemasm

    1969 Dimmer Control Needed

    It’s painful but you can replace parts on the board/in the light control box if that truly is the issue. You can take it out of the plane and troubleshoot it at the pin level. I’ll help if I can.
  14. Freemasm

    Instrument lighting issue - M20F

    @M20FTraveler,(or anybody else) if I can be of any help, just ask. I had to take mine out and test everything pin-to-pin a couple of times over the years to get it figured out and working. Still have some notes/schematics as I didn't want to live that full pain again. This assumes your’s is the same applicability or similar vintage to my 69C magical light control box.
  15. Freemasm

    Instrument lighting issue - M20F

    OK. I remembered it mostly correctly. The safe bet is one of the fuses went bad. This is what you want. the light control units have two or three power transistors. If one goes bad (which would be rare as they're old solid state/rare earth type) it would get stupid expensive very quickly. Mine was so f'd up years back I spent a lot of time to learn and troubleshoot that box. Here's a couple of pix I hope will help. Followed by a link to discussing the fuse proper. A side not to some other comments. They put a resistor in parallel with the Potentiometer/rheo and another circuit which controls current via the photocell input. These reasons and the component being older than dirt is probably why the adjustment is "non-linear." Any EE's out there, please don't condemn my response if I termed anything wrong but I'm most positive on the functionality having lived with a lot of pain it induced. Best of luck. Cheers Boys