I had a 12V outlet that was directly wired to a fuse panel - not through any relay. I had power always, running or not. It's unlikely that a GPS will run your battery down unless you leave it on for weeks on end. If you fear that someone can play a trick on you and de-juice your battery for kicks through the outlet, put a hidden switch somewhere in line and hide it Don't see a need to have the outlet run through a relay.
^^ Well it wouldn't seem like you needed one, but think of this: Let's say you overload the fuse block with too many high-current circuits (10 Amps and up). All application will work fine if switched on all at once, but the main wire feeding the fuse block has to withstand all the current you allow through the fuse block. I know, it's unlikely but let's say you run 35 Amps continuously through the block ... the wire from the battery to the block will get warm, I promise you. Protect the entire circuit with a cheap 30 Amp fuse as outlined above and you don't need to worryYaatri said:But I would put the fuse panel where the one inline fuse is, i.e. between the battery and pin 30 of the relay. If you were controlling a single circuit with a relay, you need one fuse. The fuse panel performs the same function, a fuse for each circuit, as a single fuse does in absebce if a fuse panel. NO?