Starter Fuse Blew?

[Tommy]

This is a guess because I'm not familiar with the SPF setup. But as you say there is a starter relay, this is what I would expect.

• There should be a constant +12v going to the ignition switch
• When the switch is in the START position, there should be +12v going to the relay
• There should be a larger +12v wire also going to the relay
• When the wire from the ignition switch to the relay is energized, it should close a switch in the relay allowing +12v to flow from the larger wire on to the starter
• When the starter receives +12v from the relay (or from a jumper cable if you want to test the starter), it should crank

Starters need a lot more current to work than gauges. A poor battery cable connection can allow enough current flow to operate small things, but not the starter. Check both ends of the positive and negative cables for good connections.