I replace the alternator in my chevelle to a single wire, replace the battery cables and now when I turn the key...the starter clicks once..lights go off (dome, headlights) like there is a major draw on the battery. The battery is new and charged, I even tried to jump it as to eliminate the battery as the culprit...same result. Any ideas what on earth I did when I made these changes? The starter is new and worked fine before I made changes.
:confused:

Poor connection. Check all of your connections again.

Yep...it's a connection problem.

Clean the battery terminals.

Clean the ground cable.

Clean the contacts of the horn relay/voltage regulator that rest on the front wall.

Make sure some wire is not shorting out and touching metal somewhere.