I have come up with a new product intended to make the conversion process easier. Though I have built 5 complete units (one has been temporarily appropriated for use in a demo case), the idea is still young and can be tweaked. This product is a central wiring point for all of the required or desired interlocks on an EV, such as the potbox switch, inertia switch, clutch switch, motor thermal switch, or charger. All of those devices connect to clearly marked terminals on the board. There are also inputs for the ignition and start positions of the key, so that you have to turn the car to start once to enable the system. The board then provides output to a main and a run contactor, as well as an auxiliary output for the controller to indicate that the vehicle is ready to run. The board also provides outputs for dashboard status lights.
The bottom line is, the system mostly eliminates the need for coming up with your own interlock wiring. The packaging is such that you can route wires through the box; connections are made with spade terminals. There are 120V and 230V connections to indicate that a charger is plugged in, as well as another charger interlock that can be used for a charger door switch. The interlocks are all very flexible and there are enough provided for almost any application.
This product is most useful when used with controllers such as the Curtis, that do not have enough sophistication to control their own contactors. The manual provides a complete wiring example of an Advanced DC motor and Curtis controller combination. This could also be used with a Zilla / Hairball interface by connecting the output to the charger enable input, and that enable programmed inverted (I had drawn up a complete example, but it was lost when my hard drive crashed).
My main focus right now is not to sell what I have, which is why I am not posting any prices. If you are interested in buying one, just email my user name at earthlink.net and we can work that out. I am trying to gauge interest and feedback.
Outside Picture: http://home.earthlink.net/~kittydog42/EVICC/Outside.jpg
Board Picture: http://home.earthlink.net/~kittydog42/EVICC/Inside.jpg