The "I" terminal should have a Green/Red wire going to it.
The "A" terminal should have a Yellow wire going to it.
The "S" terminal should have a White/Black wire going to it.
The "F" terminal should have a White wire going to it.
I checked the "I" terminal and it's getting 12 volts without the motor running and 14.5 with it running. Come to find out the problem is in the bulb socket in the dash. What is the correct part # for the oil and alt lights?
If you have the old bulb, you should be able to go into a parts store with large bulb selection and find the right one. Places that have the electronic catalog might even have it listed. I remember replacing some dash lights in my '65 and found lots of them at Pep Boys(the parts store I love to hate!).
If you have 12v with the key off and 14.5 with the motor running at the 'I' terminal on the regulator, then the bulb and/or socket is not the problem. Is it possible that you got those readings from the field terminal? That's going to be the one with a white wire coming out of it. Also, did this problem occur right after someone did some work on the charging system, or did it sort of go goofy all by itself? How that system is supposed to be hooked up is the green/red wire takes off towards the firewall, the white wire and the white/black take the current to the regulator from the alternator and back and the yellow wire goes back towards the passenger side, plugs into another yellow wire underneath the starter solenoid and then takes of back towards the firewall, and a big black/yellow wire comes off of the 'bat' post on the alternator and goes to the hot side of the starter solenoid.There is also a black/red wire that is the ground and goes down to the block at the same place as your negative battery cable. You might want to check and make sure that everything is hooked up correctly.