67 Dart electrical problem

If you get this fixed, YOU ARE NOT DONE!!! Check whether you have voltage drop in the harness. This will cause overvoltage at the battery.

With the key in "run" and the engine stopped, stick one meter probe into the top of the pos. battery post. Hook the remaining probe to the coil+ (with no ballast). You should be reading a VERY low voltage. More than .3V or so, (3/10 of one volt) means you need to dig into the system. The bulkhead connector, the key switch, and it's connector. Any drop (that reading) is ADDED to charging voltage.

My car had nearly 1 1/2V drop. This means that a properly working voltage regulator at 13.8--14.2 (nominally 14V) would actually run the battery up to 15.5V

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Also check the ground side of the circuit. With the engine running at fast idle, make this check first with no loads powered, and again with lights, heater, etc, powered.

Stab one meter probe into the top of the battery NEG terminal. Stab the other probe onto the VR mounting flange. You again are hoping for a very low reading, the lower the better, zero is perfect. If there is any more than .1--.2V improve the engine/ battery/ body ground, and make sure the VR is well grounded.