67 Barracuda Heavy Electric Load

wires are sized by load. Stock wires were sized by Chrysler to handle the load that they were built with. There are ways to isolate additional loads from things like electric fans, but they can't just be patched in to the original circuits without bad results.

Is there an amp gauge in the car? does it show discharge at low rpms? Is there a voltmeter in the car and what does it say when fully charged on your trickle charger, and does the voltage get lower as you drive the car? what is the idle speed in gear when the carb is off high idle? post a picture of your current voltage regulator.