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  1. Where to start moving forward 
    #1
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    I joined the Club a few years ago but I just bought my first ET, an E15 (26AE15EA). It has some downgrades: no seat switch, no break switch and it has some upgrades: Curtis 1204, a nice little hand pot, all new wiring, a real winch up front, a Lester charger, LED headlights and all new tires. Batteries are fine.


    The PO mentioned that there is a “dead spot” in the motor. The result is that I have to give it a push to go forward, and then it does not seem like full power and lately it will not even go.


    Also as you push the speed control lever forward, the volt meter goes way down (to the left). Reverse is fine and seems like normal.


    The drive motor does NOT get hot.


    The front battery and one of the rear batteries drops to 3 volts after only 4 min of mowing. The rest are at 5.95v. (are those two batteries the only ones working?).


    I have not yet tested anything.


    The manual (Fig 5.3) is not much help because of the upgraded controller and I am not great with electricity. Where would you folks start looking for the problem?
     
     

  2. Re: Where to start moving forward 
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    Senior Member FarmallMan's Avatar
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    Greetings,

    The motor dead spot can be caused by a couple of things. Either there is a low copper bar (or a couple of them) in the commutator or there is an open winding. Low bars are easily fixed by having a motor shop or a machine shop turn the armature on a lathe. An open winding is not such an easy fix, and would require either rewinding or replacement of the armature. The parts suppliers (www.electrictractorstore.com and Harold Zimmerman) should have replacements. Do yourself a favor and replace the bearings and brushes while you've got it apart.

    The fuel meter is an odd problem. It should be wired from the switched side of your power disconnect switch to battery pack negative. The only thing I can think of is that it was wired in a different way that interacts with the speed controller.

    Batteries should not discharge that much at all ever, let alone in just a few minutes. Assuming it has proper electrolyte level and is being properly charged, this is a sign of a failed battery. How is the winch connected? They can pull a lot of power, and it's possible over time they have run these two batteries down relative to the others hastening their failure.

    Nick
     
     

  3. Re: Where to start moving forward 
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    Senior Member FarmallMan's Avatar
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    Taking hydrometer readings of the problem batteries after fully charging the pack would be beneficial to troubleshoot what's going on. If you don't have a hydrometer, it'd probably be a good thing to pick up. Many auto parts stores have them, or you can mail order through Amazon or another retailer.

    Nick
     
     

  4. Re: Where to start moving forward 
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    Thanks for getting back so soon. I did get SG tester, and charged all night. The 4 newer batteries have 5.95 volts and SG 1150. The 2 older batteries are 6.98v and will not even float bulb in the meter. I assume I should start there with a couple of new batteries and then get back to you folks. I love this resource. Thanks.
     
     

  5. Re: Where to start moving forward 
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    Senior Member FarmallMan's Avatar
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    If you have access to a 6 volt charger, you might want to charge each battery separately just to insure that you're starting off on an equal footing. If you just have a 12 volt charger, then charge the better 4 in two pairs.

    As for the weak batteries, if you're a sam's club member, I have a tractor that I have been running a set of Duracell batteries in for 2 1/2 years now, and have been very happy with their performance. The price was pretty reasonable. Of course, the other brands (Trojan, Crown, Deka, etc.) will also give very good service. Let us know how you make out.

    Nick
     
     

  6. Re: Where to start moving forward 
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    I took your advice and charged up the batteries with my new (used) MK330D. The four good batteries have an SG of 1.250. The two older batteries have an SG of 1.175.

    I had the E15 motor on the bench to see if there was an obvious problem. I found some bare wires inside where the forward/reverse connectors plug into the controller. It had been rubbing against something inside.

    Should I test something? Will the motor have to be rebuilt?



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  7. Re: Where to start moving forward 
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    Senior Member FarmallMan's Avatar
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    I'm looking at a couple of things on the motor. First, it's a little hard to see the bare wire you're referencing. If it's part of the field circuit, (the small round connector on the side of the motor) and it's shorted out, that would easy to determine using a multimeter. On the ohms scale, push both probes against the steel outer housing until you get a zero (or very, very small) ohm reading. Then take one of the two probes and use it to measure resistance between each of the two pins on the round plug. You should see very high resistance (at least 5-10Kohms or higher) between either pin and the case. Low resistance indicates a fault to the case and should be addressed.

    The photo with the end cap off shows me a couple of things, first, it looks like one of the two wires has chaffed through and is contacting the case. That should be corrected with some sort of insulating varnish like this: https://www.amazon.com/MG-Chemicals-...4CS32GK0R18S0P I wouldn't use electrical tape, as it can possibly unwind. Heat shrink tubing can be an option also if you can get one end of the wire free to slide the tubing over.

    The wire chaffing should definitely addressed, but would not explain the "dead spots" in the motor's rotation.

    The commutator of the armature has a pretty good wear groove going. It looks like some of the wear patterns aren't level across the armature bars. This can contribute to the dead spots you mentioned having. The answer to that is to have a machine shop turn the commutator down on a lathe. Any reputable machine shop should be able to do this for you, or a motor shop could do it too. While it's out, I would definitely recommend replacing the bearings as well. I installed sealed bearings into all of the motors I work on, I think they're worth the extra few bucks.

    If it was my motor, these are the things I would do.

    Nick
     
     

  8. Re: Where to start moving forward 
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    Thanks Nick

    I have been racking my brains about how to get insulation on that bear wire. Thanks for solving that problem. I never would have found something like that on my own.
    As for the commutator, how to I remove it? Can I just pull out?
    The brushes are warn a little unevenly. Should I replace those also?
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  9. Re: Where to start moving forward 
    #9
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    If you unscrew the other end bell, the armature will just slide through the housing. To replace the bearings, the other end bell will have to be removed, which requires removal of the pulley and key that drives it. The bearings are just a slip fit in the end bells, so separation shouldn't be too much of a problem. If you don't have a puller or press, and you're going to take it to a shop to have it machined, they can just press the pulley off for you.

    You have two options on the brushes. First is replacement, which is the easiest and probably best. The other option is to wrap fine garnet sand paper around commutator (grit side out), reassemble the motor (brushes and all), and then rotate the shaft manually. The spring force on the brushes force them against the paper, and wear them down to match your turned commutator. This process works, is cheap, but is a pain in the rear and I wouldn't recommend it to someone new at motor work. I think new brushes and bearings are money well spent.

    Nick
     
     

  10. Re: Where to start moving forward 
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    I did get the commutator turned down. Should there be complete separation between each of copper thingies.
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