I finished changing the generator on the 57 Bird to a 1G Ford alternator. Fits nicely and no installation problems. Road tested and all is well. I have charging 14.1 Volts at the battery terminals at idle. Regular battery voltage with the engine off. No current draw with everything off. In checking everything I pulled the positive battery cable off and it quits running. I thought it should remain running without the battery with an alternator. I am using a Ford 1G alternator 65 Amp, new external voltage regulator for that style of alternator. I have a MSD Billet Distributor, MSD6 and Petronix Ignitor II ignition. Could I be losing voltage to the ignition with the battery disconnected at idle? Below is the wiring diagram I used to install the alternator.

57 Black Tbird 312/auto