Voltage from ingnition to starter relay?

1974 Dart w 318

I have not had a chance to get a FSM yet, so am hoping someone can answer a couple of questions.

When I start the engine and release the key back to the run position, the starter continues to crank.

What I've found is that the ignition wire at the starter relay gets 12v when the key is turned to start (that seems normal) but whenever the key is on, it is getting about 6-7 volts. That is not enough to trigger the starter relay, but seems to be enough to hold it once activated.

This seems odd, but I know that '74s had all the seatbelt interlock stuff (which seems to be unplugged on mine) so is that low voltage to the relay normal (in which case I guess the relay has gone bad) or is something feeding voltage to that wire that shouldn't be?

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Possibly connected with this, there is a relay on the inner fender right by the ECM, that has been unplugged and a jumper inserted into the plug. This seems to be the wire to the starter relay. Am I correct in assuming that this is part of the seatbelt setup?

Thanks,
Dan