Generator Warning Light - Mazda MX-5 Miata Sport 2007 Manual

CAUTION:

GENERATOR WARNING LIGHT

1. Verify that the battery is fully charged.
2. Verify that the drive belt deflection/tension is correct. (See DRIVE BELT INSPECTION [LF] .)
3. With the ignition switch turned to the ON position, verify that the generator warning light illuminates.
If it does not illuminate, inspect the generator warning light and the wiring harness.

If the generator warning light and the wiring harness are normal, inspect the PCM.

4. Verify that the generator warning light goes out after the engine is started.
If it does not go out, inspect if any one of the following DTCs in the on-board diagnostic system

are displayed: P0112, P0113, P2502, P2503, P2504. (See DTC TABLE [LF] .)
GENERATOR
Voltage
1. Verify that the battery is fully charged.
2. Verify that the drive belt deflection/tension is correct. (See DRIVE BELT INSPECTION [LF] .)
3. Turn off all electrical loads.
4. Start the engine.
5. Verify that the generator rotates smoothly without any noise while the engine is running.
If there is any noise, find the cause and repair or replace the generator.

6. Measure the voltage at each terminal using a tester.
Generator standard voltage [IG-ON]
Terminal B: B+
Terminal P: Approx. 1 V or less
Terminal D: Approx. 0 V
Generator standard voltage [Idle, 20°C {68°F}]
Terminal B: 13-15 V
Terminal P: Approx. 3-8 V
Terminal D: Turn the electrical loads (headlights, blower motor, rear window defroster) on and
verify that the voltage reading increases.
2007 Mazda MX-5 Miata Sport
2007 ELECTRICAL Charging System - MX-5 Miata
Do not apply direct battery positive voltage to the generator terminal

D, otherwise it could cause damage to the internal parts (power
transistor) of the generator.