74 Duster Fusible Link

Great advice.
The '74 diagrams requires some assembly.
The diagram here is redraw of the factory diagram but showing only the main circuits.
https://www.forabodiesonly.com/mopa...wed-by-quick-recovery.547042/#post-1974415233Notice where the fusible link is.

If you had observed the ammeter before you disabled it, if it moved to max discharge as the link started to smoke, then the short is further downstream.
As noted above, the regular fuses would protect from a short downstream of them. In other words the fuse would blow before the link failed. So that narrows down the location of the short.

This next thread is an example of working with the '74 factory diagrams to track down the cause of a fuse blowing
https://www.forabodiesonly.com/mopar/threads/turn-signals-not-working-blowing-fuse.508597/Once he systematically disconnected the connectors, the branch with the short was then identified.

Note: If your car has an electric defrost grid on the rear window, it has a slightly different main wiring arrangement.