71 Dart overcharging

The fastest,easiest test that your system is OK, and the voltage drop between the
batt. and the ign.2(dk blue)circuit is the issue,is a long jumper from the pos.post
to the front back probed in the blue wire at the alt.It needn't be heavy,it will
simply present the 15.5V to the volt sense side of the reg., it should drop the volts
at the batt. steadily and immediately.If so,proceed w/67's advice and find the drop,
and yes,hi-output coils w/low ohm ballasts WILL cause a drop in the ign2 circuit.I
just did this to a cuda,and used the blue wire at the ballast to energize an OE FWD
mopar EFI relay to power the ballast and coil stand alone,and maintain a factory
appearance w/the metal cover etc.
As far as ground issues go,and i know this is a little scary, but i have experienced
resistance across body panels.In other words,say between the cowl and main firewall
etc.,the parts are spot welded,but there is a lack of electrical integrity,just another
thing not to take for granted.
Good luck and let us know what you find:coffee2:
P.S. you didn't say what V reading at alt output post? Jumping from that to the backside of the
blue V in term on the alt should also drop the output the same as a batt. jumper.