So here is the deal, most of the time when I brake hard at all my battery gauge drops into the red. It only does it when I'm brakeing and if I brake verylightly it dosen't do it. Well it has now gotten to the point when it stalls the car, it just stalled on me in the middle of the highway. It always starts back up. It had been getting harder and harder to start, well just taking longer when I turn it over. So I thought maybe the starter, because the battery and alternator were replaced less than a year ago, and they were not replaced with the cheap ones. I checked my connections to the battery and alternator and everything is good. I was thinking the starter was going out but I don't know, would that cause that to happen when I brake. I guess maybe it's a fast drop in RPM's that causes it, but I don't know what "it" is.

 

Don't know if I can help, but here are my thoughts. When stopped, push the brake hard. If this causes the problem you need to check out the brake light circuit. If not, try it at a very low speed. If this happens only at higher speeds I would also check to see if the momentum is causing a wire to make contact with some metal and creat a short.
Good luck.

 

I agree with the previous post. The other thing is to look at the battery connections. With the side mounted terminals, there are times when the holding bolt bottoms out on the hole and feels good & tight, but the cable is still loose.