I do not know much about the charging system on my 64 Galaxie wagon other than it is still using a generator and everything seems to be working fine. Today, for the second time, while driving into work the "GEN" light would faintly come on intermittently. Is this a warning that the generator or the voltage regulator will soon need replacing? It only does it occasionally and only after about 20 minutes of driving. It does go off for awhile and never stays on consistently. The car has the stock 289. Thanks for your help Rodney
May be nothing more than bad battery connections. Clean all four points and extra grounds, if it has them.