Buka bonet enjin kereta, start enjin, ON lampu kereta, ambil Multimeter Digital/Analog, letak +ve Prob di +ve bateri & -ve Prob di -ve bateri, tengok bacaan kalau 14VDC alternator dalam keadaan Elok, kalau bawah 12VDC alternator perlu servis atau tukar baru.
Open your car engine bonet, start your car engine, Switch ON car lamp, take your Analog/Digital Multimeter, put +ve probe on +ve battery & -ve probe on -ve battery, see reading on multimeter if reading in 14VDC, your car alternator in good condition, if reading under 12VDC, car alternator need to service or replace new one.