External voltage regulator location

On the earlier 4 cylinder Troopers they used external regulators that were mounted somewhere on the left side.

I started having trouble starting the car a few months ago and ended up replacing both the battery and the alternator, which seemed to fix the issue. But about a week ago it began having trouble starting again. I tried just charging the battery. But it would quickly begin showing those same issues. I tested the battery and it was a little low but within the required CCA. I figured that the only other thing would be the starter, so removed it and had it tested, It came back as positive and working fine. The only other thing that id new was the voltage regulator.