[Lynn Eades]

Many older vehicles can be converted from +ve earth to -ve earth by changing the battery around, and re polarising the field magnets in the generator ( as simple as wiping a wire,hooked to the new live terminal of the battery, to the little terminal of the generator)Any alternator is not able to be changed easily. Instruments are not usually polarity sensitive, but some are.Generally speaking, fuel, temp, ampmeter,and oil pressue gauges are not polarity sensitive. Its generally the charging system that needs the attention. repolarising the 'fields" as I have just mentioned is all that is needed, but it must be done immediatley after the battery is reversed, and before the engine is run up. Otherwise the regulator and generator will burn out. Usual warnings, Check with an auto electrician.