normal idle speed engine dies under electrical load on 2003 Mitsubishi Eclipse

V6 engine (95,000 miles)just recently started dying at stop lights when idling with A/C on you roll-up power window(s) or increase the elerical load,
Alternator output drops to about 11.7 volt on shop meter, engine idle drops to about 600 RPM, engine starts to loap, and dies. Will restart easily. Already tried new alternator and battery, seems to search for more idle RPM's. Maybe Electronic Control Module ? Maybe an electrical short in wirring ?

Asked by for the 2003 Mitsubishi Eclipse
If the Alternator drops to 11.7, that is a critical error, a charging system should never go below 14.1 volts, ever! What is the idle rpm when it is reading 11.7 volts?
Believe we have located the problem to be a bad coil/distributor.