Ammeter Maxed

I recently got 1973 Plymouth Valiant with a 318. It died while driving about a month ago. I jumped it and got home but it seemed like it wasn't getting charge. I replaced the battery, alternator, and voltage regulator but now I'm noticing that the ammeter / alternator gauge starts to max out upon accelaration. The ammeter needle is around the middle upon startup and for the first few minutes or so but once the electric fans kicks on the ammeter shoots up and maxes out with any acceleration. It hovers to the right at idle, but jumps to 40 with any gas. If I turn on the headlights, it jumps a bit higher at idle too. The voltage regulator feels hot but to be fair its been really hot out. The previous owner made a mess of the wiring so it's hard to pin point the problem. I'm assuming its not safe to drive like this and I'm at risk of melting something, but I'm not sure where to start. Any tips would be great