Galant ES Stalls and Battery Drains/Electrical

Hey everyone, haven't been on as much as i would like due to work and classes but I was hoping some of you knowledgeable gents could provide some advice or solutions on what is wrong with my Galant.

So the story is this:

I originally noticed a problem when my radio just started loosing power intermittently. Ok, I thought a cable had come loose and was going to check it when i got home but as soon as my radio started acting up both my headlights and dash started dimming and my car started chugging. It would not accelerate no matter how much i pressed down on the gas. Then all of a sudden it went back to normal.

Drove my car fine until the exact same thing happened again a couple days later except this time my car died after it started chugging and would not start or crank at all. Turns out my battery was completely drained.

I took out my battery and had it tested at Advance, battery is completely fine. I then moved on to other possible causes that were pointed out and as such replaced the alternator and ignition switch. That seemed to have solved the problem until yesterday when my car started doing the same thing again on the highway. After it started chugging it would not accelerate no matter how much gas i gave it then died. Car would not even crank and my battery was drained. thing is as soon as i passed cables to my car it started up fine- that is until it did the same thing later.

I have no idea where to go from here so i would appreciate some advice. Though i should probably say that I'm somewhat of a novice mechanic.

Thanks.

So what have you replaced?

So far I've replaced the alternator and the ignition switch (opposite the key cylinder). That's as far as my knowledge of possible causes went.

I'm not 100% sure, but if I remember right, someone on TGC had mentioned that you could have the ground cable disconnected from the frame. If I remember right, it's at the back of the engine on the firewall.

The Main window switch on the drivers side sometimes gets a short and drains the battery too.

Thanks, I'll check the grounds and switch when I wake up later today. However, I was wondering: is that the only ground or are there more that I should check?

Do you have an aftermarket radio? As far as I remember the main ground is the ground strap under the hood connected to the firewall.

Find out what its charging rate is with car running and all accessories on. Should be high 13+ volts. They should do it free wherever you bought the alternator if you don't have the ability to do it yourself. The main ground attaches to a starter bolt at the bellhousing. Use a terminal cleaner or wire brush to clean battery cables and terminals at battery.

if you were to start the car and turn on all the accessories on you will start out seeing high 13s but it will steadily drop because the output cant keep up with the demand at idle so just checking without all the accessories on you will see what the system is putting out should be around 14vs as cars are a 14v electrical system. look for corrosion or lose connections first, dont keep throwing parts at it hoping to fix it as you will waste time an money.

It sounds like something that was happening to my Galant earlier this year.
The car kept stalling when I would turn it on. I was told it was a sensor on or by the throttle body. Hopefully this helps.

Mine did the exact same. Look in the fuse box underneath the hood. There is a diagram that says Alt choke in the corner of the diagram, Check BOTH of those fuses.

A little food for thought, if you trace the wires connecting to that fuse, one goes to the alternator, the other goes to the battery.
It's a quick simple fix. Takes like 5 minutes at most.