Probably not. I'm all but certain that an inverter/charger was standard equipment on your 96 Eagle and, if so, it definitely functions as the converter as well. Any combination inverter & charger provides 12v conversion as part of its function. If, however, you have a standalone converter (no charging function), then you will have a converter/charger somewhere. If won't be hard to find, cause it will have major size cables to the batteries.
If you can give me the brand and model number from that inverter, I can put your mind at ease.