ALTERNATOR NOT CHARGING BATTERY

1988 Mazda MX6

Tiny

CARLOSGARZA

March, 4, 2010 AT 11:56 PM

Electrical problem
1988 Mazda MX6 4 cyl Front Wheel Drive Automatic 180000 miles

MY ALTERNATOR IN NOT CHARGING THE BATTERY WHEN THE CAR IS ON. THE BATTERY VOLTAGE WHEN CAR IS ON IS ABOUTN 12.7V AT IDLE. BUT IF BATTERY CABLES ARE REMOVED WHEN THE CAR IS ON, THE VOLTAGE ON THE CABLES GO UP TO 14V. WHY IS MY ALTERNATOR NOT CHARGING WHEN I CONNECT THE BATTERY BACK AGAIN?

FOUND 297 RELATED QUESTIONS

5 Answers

Tiny

rasmataz

March, 5, 2010 AT 12:04 AM

Get the alternator and regulator checked out and inspect wiring.

Tiny

CARLOSGARZA

March, 5, 2010 AT 12:25 AM

ALTERNATOR AND WIRING TO FUSE BOX AND WIRING TO
BATTERY ALL CHECKED OUT GOOD

Tiny

rasmataz

March, 5, 2010 AT 12:32 AM

Refer to the charge system EWD


http://www.2carpros.com/forum/automotive_pictures/12900_c1_26.jpg




http://www.2carpros.com/forum/automotive_pictures/12900_c2_24.jpg

Tiny

CARLOSGARZA

March, 5, 2010 AT 12:46 AM

POWER CABLE FROM ALTERNATOR TO BATTERY HAS BATTERY VOLTAGE, SO DOES THE WHT/GREEN CABLE. AND WHT/BLACK ONLY GET BATTERY VOLTAGE WHEN THE IGNITION IS ON. MY CAR HAS NO ABS. AND WHAT IS 4WS RELAY AND TIMER UNIT?

Tiny

rasmataz

March, 5, 2010 AT 1:04 AM

Do the test below: 1. Connect suitable ammeter between B terminal wire and B terminal. Be careful not to ground B terminal.
2. Turn all headlights and accessories on and depress brake pedal.
3. Start engine and check output current at engine speed of 2500-3000 RPM. If output current is 65 amps or more on MX-6 and 626 or 60 amps or more on 323, alternator is satisfactory. If not, proceed to step 4.
4. Turn all electrical loads off and release brake pedal.
5. Check output current at engine speed of 2500-3000 RPM. If output current is 5 amps or greater, proceed to step 6. If not, proceed to step 7.
6. Check output voltage between S terminal and ground at engine speed of 2500-3000 RPM. If voltage is 14.1-14.7 volts, proceed to step 7. If not, there is a poor connection between B terminal and positive battery cable, between negative battery cable and battery or between alternator 2 pin connector and positive battery terminal, or stator coils or diodes are malfunctioning.
7. Turn ignition switch On and check voltage at L terminal. If voltage is 1-5 volts, alternator is satisfactory. If not, IC regulator, brush or field coil is malfunctioning.

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