Before going to the effort of removing the alternator, I would run basic tests on it alone. You can do that w/ a few jumpers, to bypass the run thru the cabin and key switch. Install the Vreg right next the alternator w/ your own wires to bypass the car's harness. Takes a little knowledge, which can come from reading the responses here, looking up the gazillion posts on this by 67Dart273, youtube's, etc. If you won't do that, take it to an expert.