If you don't have fusable links, check for an aftermarket fuse that may have been installed or like the previous reply for some new electrical tape. A digital voltmeter (go cheap if you just use it minimal) will help you figure out if you have a draw with the key off engine off or like the previous reply key on engine on doing his method. I tested mine, I think I put one end on the negative terminal and the other on the end of the negative connection to pull the reading of draw (key off engine off) and since it read voltage I had a draw, while it was off. Keep in mind there are two theories of how electricity flows, Positive to Negative and Negative to Positive. In automobiles, you end up using a little of both, they are wired for Positive to Negative trouble shooting but if you're looking for a draw with the engine off your testing the opposite since that's really the direction it goes. Those two theories help a bit when you're troubleshooting with a digital voltage ohm meter.
**Anyone correct me if I'm wrong, it happens and I'm not afraid to admit it.
As for the dying while running, also keep an eye on that voltage gauge while you're driving. Innova makes a $60 voltmeter where you can check the alternator while the car is running to find out whether it's within specs, rather than have to always go to the Zone and waste an hour of your day. I have a repair manual for 77, which should be very similar to your year, PM me and I'll get it to you.
Speaking from experience here... don't go throwing parts at it until you know the problem. They all add up quickly, slowly killing the budget. I did that with my current project and wasted WAY too much money. Now I'm struggling finishing it.
Last thing here... take a picture of some of that wiring, like the one you posted originally but your car this time. I think a lot of these guys in the forums know what looks right and what looks wrong who can point you in the right direction.