if you have no VR then you must have an alternator rather than a generator - if you hook one side of the ammeter to ground have a fire extinguisher handy, there is no ground terminal on an ammeter .... the ammeter measures the flow of current to & from the battery, one side connects to the supply [alternator] the other side connects to the positive post of the battery - actually usually someplace like the large hot terminal on the starter .... please study the wiring diagram linked above and study up on auto electric systems a bit or find someone nearby to help you out in person
the oil gauge [mechanical] takes a small tube with a ferrule on it and a ferrule nut - you should be able to source that at a FLAPS, the one from the aftermarket gauge may be different
Bill
