72 Dart Swinger Fuse Blowing (New to Older Cars)

A quick history of the car:

Recently bought this car as my first "big boy toy" as a young adult. 1972 Dart Swinger that has a 440 (1973 if I read the casting number correctly). The entire time I have owned the car I have been keeping it in my dad's garage 90 miles away. I wanted to build up some trust in the car before I brought it to house since I have little to no room to work on it for the next couple of months. I usually make the trip twice a month to see the parents and have been tinkering with the car so my ability to respond with pictures is not going to be speedy.

The issue I'm having is with a 30A in-line fuse that leads right into the bulkhead connector. From my reading on these forums I'm guessing this is the main power source to the ammeter (is this a replacement for the factory fusible link?). The ammeter has never shown a reading so I assume a previous owner bypassed it. Haven't had the dash apart to verify. There is an aftermarket electric fuel pump, BeCool radiator with electric fans, and electric water pump. Additionally on the switch panel there is a fourth switch labeled alternator. I was told this is to disengage the alternator in case I wanted to take the car to the strip. The battery is located in the trunk of the car and is an optima yellow top.

The fuse started blowing consistently after about the third or fourth drive after I bought it. The car will start and drive fine. All accessories work until we switch the car off. At that point you can't get the accessories to come on, lights, dome light, gauge lights, nothing...blown fuse. It doesn't necessarily blow every time the car is started because I've made multiple trips on a fuse before it blows again, but seems to blow about 75% of the time if the car is started for carb tuning or driven.

My plan is to be able to take all pictures necessary next time I make the trip home so I can post here.

The first time I could tell the fuse blew was when I had the door open while we were tuning the carb. I noticed the dome light clicked off so we checked the fuse and it was blown. If I recall correctly, after the fuse was replaced I remember thinking the dome light never came back on.

I know the alternator has the main black wire and two field wires. I understand that one of these (green) goes to voltage regulator and the other to the starter switch. I just replaced the alternator because the battery kept losing charge but it makes sense now that it was never charging correctly.

Dad said the headlights get brighter if you increase the rpm.

Can anyone give me an idea of what I could do to narrow the problem down so that I can gather the necessary information next weekend when I visit? Thank you all in advance for your time! I'm looking forward to ironing out the kinks and really getting to enjoy the car this fall.