We have an older english bus on which we need to install Geotab GO gps unit. The older bus doesn't have the OBD-II (On-Board Diagnostics II) port. How can i connect the Geotab GO device to the 12 volt and ground directly. What is the pin out on the GO device for connecting to +12v and ground. Are there other pins on the Geotab GO device that I have to connect to some other signals on the bus as well besides the 12v and ground ? This bus is from 1992, so this before any type of OBD type of ports were invented. Any help you can provide me would be so much appreciated. Thanks ever so much. Sam