Checking my alternator
- Thread starter Jack
- Start date
Your 60A alternator can only produce that rating for a few minutes at best, and this is into a lower SOC bank. If you fire up the engine and the alternator is increasing battery voltage, it is working. The best way to test it is with a battery monitor that can show current or a DC clamp meter.
You could use a clamp on amp meter and a 100 amp battery load tester. Put the amp meter on the output wire of the alternator and attach the load tester to the battery bank, apply load & read amp meter. You should probably rev the motor to about 1500 rpm. Easy.
- Observe the battery voltage before starting the engine - It should read somewhere around 12.5-12.65 volts.
However, If the battery is low you may want to have it load tested.
- Read the voltage on the meter - Start the engine and observe the voltage on the meter. The voltage should read a minimum of 13 volts. A good alternator should put out somewhere between 13.5-14.5 volts.
- Stress test the alternator - Place a load on the alternator by turning on the lights, the radio, TV, Fans, Blower and any other power drainers. Now check the voltage across the battery
If the voltage is low, you can lightly wiggle the electrical connections on the back of the alternator to see if the voltage changes. If it does then it may just be a bad connection. Loose or corroded connections on the alternator or the battery can cause bad alternator readings. - The voltage remains high with these circuits on. If the voltage does not change when the engine is started, if it does not get above 13 volts, or if it charges above 15 volts then the alternator may be faulty.
Note: If you do not know how to use a digital voltmeter for checking voltages. I would recommend getting a professional to check it for you. also DVM meter won't tell you how many amps are being generated
Best Regards, Capt.Rob