Forgive my green question as I'm relatively new to Datsuns.

Heater blower and choke/seat belt/defrost lights don't work. Are these on the same fuse? All fuses look intact. Are these issues potentially linked in any way?

Could it be a fusible link that's melted? I may be stretching on this one.

I assume you're talking about the 73. No, they are on completely different circuits. Look at the wiring diagram in the FSM. The White/Red wire (main power) branches off to a 20A fuse inline fuse. The other side of the fuse is a Blue wire. It goes through the accessory relay and come out as a Blue wire. That wire goes to the blower motor. The common thread is that the wires are in the dash. Remove the center console and the fan controls to look for damaged/hacked wires or disconnected wires. For whatever reason, the FSM doesn't have anything that I've been able to find to describe the blower motor aside from the wiring diagram. If you look at page BE-3, you'll see where the connections are for the lights.

If your fusible link was gone, you'd have a lot more problems than the blower motor and warning lights.

Yes, I was referring to a '73 (forgot to mention that). I've got spare heater controls & and spare blower motors which I can use for testing purposes. Thanks for the info! Time to pull out my multimeter.

I agree, check for power and ground on those circuits. The circuit diagram in the FSM is a little hard to follow but it did help me in chasing down the damage. When my voltage regulator failed, it was my accessory relay that melted.