Everywhere I dig around the web (in forums etc.) I see people not recommending more than 12v to go on an automotive relay.
Let's look at this one for example:
I understand they have been designed for 12v systems but the vast majority, if not all, have rated amps on them.
AFAIK conductor cross section requirements have no relation to voltage so if it can carry 40A at 12v it should be able to carry 40A at 50v or any arbitrary, reasonably high, voltage. That is until we get to the point where the voltage gets so high that arcs could jump through gaps between the inside components of the relay but that would be way out of the league of anyone like me.
I'm suspecting the posts I found which discourage going above 12v are regarding the energizing voltage, and not the carried voltage.
Is my guess reasonable and would it be possible to use higher voltage on the NO/NC paths of relays such as the one shown above?