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Repair J1772

Discussion in 'EV (Electric Vehicle) Discussion' started by bwilson4web, May 19, 2018.

  1. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Prime Plus
    BACKGROUND

    About three months ago I fell against the J1771. The next morning I found the car had not charged; the plug was at an angle because the latch tooth had broken off. It would still charge our cars but the proximity sense did not work unless I manually remembered to push the latch.

    A couple of weeks ago, I bought a replacement J1771 connector from Amazon and installed it on the BMW L1 charger.

    Survey Replacement

    The first step is to disassemble the replacement. It came in without any instructions so this assumed some degree of understanding.

    The shell is held together by Torx screws that were easy enough to remove:
    [​IMG]

    Inside we find a the push button lever that activates a micro switch. This is part of the proximity sense circuit the car uses:
    [​IMG]

    The plug is sealed using triangle screws. So I went to my favorite hardware store and bought a tri-wing bit which worked close enough for this first attempt:
    [​IMG]

    So here is the shell, plug, and plug cover:
    [​IMG]

    With the switch not activated, we measured 150 ohms:
    [​IMG]

    Activating the switch, the resistance increases to 479 ohms that signals the car should stop charging. This avoids "hot" plug and unplugging that can lead to connector wear from small arcing:
    [​IMG]

    Here are the parts of the plug:
    [​IMG]

    There are five pins: ground is on the tab side; at the 2 o'clock position is the proximity pin; at 10 o'clock the pilot signal; 5 o'clock is the 'HOT' pin (black wire), and; 7 o'clock neutral:
    [​IMG]

    This shows how the pins fit in the plug assembly:
    [​IMG]

    Here you see all subassemblies together:
    [​IMG]

    I bought a new stripper sized for power cables and a crimper tool. Sad to say, the crimper did not work out:
    [​IMG]

    Broken Connector

    Here we see the broken tooth off the retainer latch:
    [​IMG]

    My Torx bit did not work because of the center pin. So I bought a set of security Torx bits:
    [​IMG]

    The inside of the 2014 model year, J1772 was very busy:
    [​IMG]

    Here is the latch with the micro switch and bundled wires, tie-wrapped together:
    [​IMG]

    Here is the microswitch that converts the red and black wires to a ground and wire for the proximity circuit:
    [​IMG]

    The next problem was the grommet that brought the cable into the handle. There were different sizes and incompatible:
    [​IMG]

    The replacement grommet on the left is sized for a larger cable. The original cable only had to handle 15A so it was much smaller.
    [​IMG]

    My fix was to wrap the cable with plastic tape to increase the diameter. This solved the grommet and internal cable strain relief clamp:
    [​IMG]

    So I threaded the wire through the five connector holes and only needed to crimp the connectors:
    [​IMG]
    Unfortunately the blue, pilot signal wire would not fit through the black plastic hole. So I used a drill to make it a little larger to fit.

    There are three different connector styles. The HOT and NEUTRAL pins are identical. The ground pin is longer. Curiously the proximity and pilot pins are not identical:
    [​IMG]

    The proximity pin on the left is slightly smaller than the pilot signal pin on the right:
    [​IMG]

    Try as I might, I could not crimp the pins. So I soldered them:
    [​IMG]
    Due to the size, a strong, solder gun is needed. But these solder cups do not have an air escape hole in the base. Solder can not flow through the whole length of the cup due to the trapped air.

    The first plate on the left holds the pins into the connector assembly. A single Torx screw holds it, The comes the orange, water resistant rubber assembly. On the right is the last plate that forms a wall to the interior of the J1772 shell:
    [​IMG]

    Another view showing the single Torx screw:
    [​IMG]

    The water gasket is seated and the back plate ready to compress the gasket:
    [​IMG]

    Here is the unit ready to seal up:
    [​IMG]

    Finally, everything is ready for the smoke test:
    [​IMG]

    CONCLUSIONS
    1. Assemble the J1772 using standard wire leading to four, automotive style, crimp connectors. This avoids having to fiddle with threading the power cable wires into the plug and a lot of experimentation.
    2. These are solder connectors so drill a small hole at the base of the cup so the solder can flow through and fill it completely. Since I did not do this, I'll use an IR thermometer to make sure there are no temperature hot pins.
    3. Wrapping the smaller cable with plastic tape is better than nothing, it is not an optimum solution. I will continue to look for better solutions like liquid tape and hoses whose internal and external diameters to fit.
    Bob Wilson

    ps. Before doing the smoke test, I noticed the AC plug was discolored so I opened it up:
    [​IMG]
    [​IMG]

    So much for a water-tight, NEMA 5-15.
     
    #1 bwilson4web, May 19, 2018
    Last edited: May 19, 2018
  2. hill

    hill High Fiber Member

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    Location:
    Montana & Nashville, TN
    Vehicle:
    2004 Prius
    Model:
    IV
    Recently, I decided our original aerovironment evse should be updated from a 12'cable to a 25-footer. The purchase included a new nozzle. Some days, you just can't even give stuff away .... I offered to ship this off to anyone who wanted it here on PC - to no avail;


    20170326_144049-1.jpg

    A few months later, the thought crossed my mind - if we ever needed to charge super fast at home - i could pick up an EVSE super cheap on eBay because some clever Canadian fella realized he could buy a bunch of Tesla Hi Power wall Chargers (HPWC's) & take advantage of huge incentives for each one. That allowed him to sell all of them for $300 (including shipping) & still make a sweet profit.

    Sold the Aerovironment evse for $100 to a co-worker who has a Ford PHEV. MAN - there's not much to these things at all. And originally these pigs cost $1,000 not including installation
    20170326_142859.jpg
    Live & learn.
    Still have the original 12 foot cable with nozzle if anybody needs one.
    .
     
  3. plug-it-in

    plug-it-in Active Member

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  4. plug-it-in

    plug-it-in Active Member

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    Congratulations and thank you. Very well done.

    To thicken the wire you might try heat shrink tubes of increasing sizes over the cable. This solution worked for me in the past.