Battery Overcharged

1. Inspect output voltage as follows:
a. Turn off all electrical loads.
b. Disconnect alternator B terminal electrical connector, then connect suitable ammeter between wire and terminal.
c. Charge battery until charging rate indication becomes less than 5 amps or replace with new battery.
d. Read meter at engine speed of 2500 RPM. If meter reads less than 5 amps, proceed to e.
e. If terminal B is less than 5 amps, measure voltage at L terminal at engine speed of 2500 RPM. If meter reads more than 15 volts at 68° F on all 1986 models, 1987 323 or 1988 RX-7, or 15.2 volts or more at 68° F on 1987 626 and RX-7, proceed to step 2. If meter reads 14.4-15 volts at 68° F on all 1986 models, 1987 323 and 1988 RX-7, or 14.2-15.2 volts at 68° F on 1987 626 and RX-7, alternator is satisfactory.
2. Inspect IC regulator power source as follows:
a. Disconnect alternator R connector on all 1986 models, 1987 323 and 1987-88 RX-7 or alternator L and R connector on 1987 626, then place ignition switch to On position.
b. Measure L and/or R terminal voltage at connector, then reconnect connector(s). If meter reads battery voltage, proceed to step 3. If meter reads less than battery voltage, wiring harness is defective.
3. Inspect rotor coil as follows:
a. Place ignition switch to Off position, then disconnect alternator B terminal on all 1986 models, 1987 323 and 1987-88 RX-7 or alternator B terminal and L and R terminals at alternator on 1987 626.
b. Measure resistance between alternator L and F terminals. If meter reads 3-6 ohms on 1986-87 323 and 626, 2-2.6 ohms on 1986-87 RX-7 models or 2-4 ohms on 1988 RX-7, IC regulator is defective. If meter reads other than 3-6 ohms on 1986-87 323 and 626, 2-2.6 ohms on 1986-87 RX-7 models or 2-4 ohms on 1988 RX-7, rotor coil or slip ring is defective.