A new suspect in the case of failed chargers!

This one beat me up pretty bad before I figured it out:

In the wire harness that connects the EVSE charge port to the PCU there are crimped barrel splices.  I found one of these splices to be an intermittently open circuit.

This will be an additional mandatory retrofit to every Think that comes in with a no-charge condition.  So in addition to removing the FU2 and FU3 (replacing with jumper wires) and installing inline fuse holders in the EVSE wire harness, I will also be removing the crimped splices and replacing them with a solder splice.  It might not be a bad idea to do this as a preventative service, too.

I believe that the Thinks were shipped from Finland to Indiana with an EVSE connector that is different than the J-1772 standard that we use in the US.  And thus, I suspect the connectors were loped off and new ones installed.  The protective orange loom that encloses the EVSE wires changes from one shade of orange to another shade about 1 foot from the EVSE port, behind the left front fender, and the joint is covered by black heat shrink.  The crimped splices are in this same area, so the left front fender must be removed to access them.

I would like to know exactly what signals the various wires carry.  The larger wires (black, blue and green/yellow) are obviously for main line voltage, neutral, and ground.  I put an oscilloscope on the other smaller two wires while I had a vehicle charging, and it seemed that one was just ground with some noise and the other looked like a pulse width modulated signal at 1 kHz.  With a level 1 Leviton EVSE it went from about 12% to about 22% after I pressed the button on the EVSE to raise the charge rate to 12 Amps.  Can anyone out there please explain to me exactly what these wires do (or are supposed to do) according to the SAE standard?


3 thoughts on “A new suspect in the case of failed chargers!”

  1. The two signals you are wondering about is the J1772 pilot signal (CP) to tell the car how much amp it can draw and tell the charger that a car is connected and ready to charge. https://code.google.com/p/open-evse/wiki/J1772Basics

    Tje other line is a proximity switch (a magnetic sensor in the think) to tell the vehicle to stop charging if someone start pulling out the contact.

  2. Oh yes, the Pilot signal.
    In the initiative ‘Open EVSE’ I found good information years ago.
    Here is a link:
    Then click left on >> J1772.pdf
    The wiring: My TH!NK has the plug type Lewden. USA-TH!NKs has J1772.
    Excerpts from ftp_asgren plans (yahoo_group_think_ev / files):
    #AC_inlet_Lewden_ J1772_wiring.pdf




    You see, Lewden plug has 6 pins connected, J1772 just 5.
    Why? — Proximity in Lewden with permanent magnet. In car-plug sits a reed contact. In J1772 works an micro switch.

    Here in the EU Think had been delivered with charger cable and ICCB of Kitron / Billingstad-Norway. ICCB Pilot selection 10 or 16A.
    But real maximum my device is 13,4A.
    On the grid side is an Schuko connector (Old poor construction).
    The allowed according to the rules of the art (VDE, IEC, …) in the long run only 13A(25grdC).
    Merci ….. HANS

  3. Crimping is superior to solder in high current applications.
    Re: J1772 connector.
    Looking into connector on the car.
    The upper two large pins are L1 and L2 AC lines.
    Same as on an electric dryer, range, or water heater.
    The lower large pin in center is ground.
    If GND pin conducts over 20ma , charging shuts down for safety.
    The small pin on lower left is 1khz pilot.
    The small pin on lower right is proximity.

    The % duty cycle of the 1 kHz signal tells the car the maximum current it can draw from the EVSE. When you pressed the button on your Leviton, it changed its % duty cycle on pilot signal to what corresponds with 12A. The Think sees it and draws 12A. My Think only draws 14A max on 220V even if it sees a 30-80A pilot signal.

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