[Walt Fricke]

You sure you have the VR hooked up right? The '77 (mine, anyway) came with the external VR, which is easy to replace. But I recall the connection from the alternator to the VR was a three female pin molded plug, so hard to miswire.

Next step would be to pull the alternator and take it to a shop which tests such things. If the VR replacement won't fix it, it pretty much has to be in the alternator itself - a bad diode or so somewhere inside, or some kind of internal short. 17V is way too high. At 15+V I started smelling sulfuric acid smells from my battery.