In the early days of transistone auto radios there where radios with switches to convert from negitive ground to positive ground , very few imported cars and trucks had radios in them at that time,many USA radio manufactors made radios for these imports, I have a MOTOROLA built radio for a late 50's Volvo, it even has "VOLVO" on the dial .
I have a transitor[hybred] Stromgburg Calson 12volt + or - ground and I've also have two Mack truck radios ,transistor , that can also be played on + or - ground .
