Another reason for a regulator to full field when it shouldn't is poor connections in its circuit - usually a bad terminal crimp or oxidation at the bulkhead. If the regulator see less the 14.5 ish Volts, its going to let more current through to the alternator's field. The regulator here is just doing its job. If its getting under 14.x volts, it thinks the alternator isn't putting out enough power.