If the voltage at the voltage regulator ignition wire is only 14.5 volts when the alternator is putting out 15.5 volts then the regulator thinks the voltage is where is should be. are losing 1 volt somewhere between the battery and the regulator.
Exactly correct and I've written about this many times. Voltage drop in the harness, from battery to the VR. Bulkhead connector, ignition switch connector, or ignition switch.
