What should be the expected voltage on pin 30 of a starter relay?

I was doing some research about how a pin 30 works on a relay and basically it said that this should be wired through a fuse to the battery. I checked the voltage on the relay slot where the starter relay is supposed to go and Pin 30 has no volts, pin 86 has 12v. My question is, what should be the expected voltage on pin 30 of this slot? The truck does not start, I have not replaced the relay just yet. But it does turn on if I manually press on the relay coil.