thanks for the answer but how do you tell if they are 6 or 12 volt??

should have mentioned this is for oz and we got stuff later than U.S and usually a bit mixed .for oz 55-56-57 customline used the same cluster, ,the half round with 2 gauges sometimes called moonlight dash over here . 55 was 6 volt for us and 56-57 was 12 volt with the same dash and dials.so far so good. now the fun bit. on a recent visit to the speedo repair shop he spelt it out to me very clearly that my gauges are 6 volt even though it is a 12 volt car ,of course i said they may have been mixed up over the years ,but after supplying him with variuos sets he set me straight and said they used 6 volt on all those model australian cars.so can anyone tell me how they reduced the voltage down to 6 volt for the 12 volt cars??he suggested for the temp they used the large temp sender and the resistance on that done the job .not sure about the fuel .i think i will stick a resistor behind the dash.