With the battery fully charged (12.68 Volts) and a volt meter connected to the positive and negative battery posts, run engine at idle with no accessories on, voltage reading should be aprox 14.2.
Alternator is defective.
To test an alternator for voltage, start by using a multimeter set to measure DC voltage. With the vehicle running at about 2,000 RPM, connect the multimeter's positive lead to the alternator's positive terminal and the negative lead to a good ground. A functioning alternator should produce a voltage reading between 13.8 and 14.5 volts. If the reading is significantly lower or higher, the alternator may be faulty.
If your battery was dead and you jumped it to get it started and the gauge shows your not charging you need to replace the alternator.
From 13.5 to 16 volts.
From the alternator to the battery should be 14v
By buying a Chilton or Haynes manual and reading
Not necessarily. There are a lot of factors that can keep you from reading 14 volts at the battery, such as corrosion in the cable from the alternator to the battery.
I would suspect that the alternator is failing. Have it load tested at your local auto-parts store.
Connect a voltmeter across the battery terminals without engine running reading should be around 12.8 With engine running reading should be 13.8-14.2 if you are getting these numbers alternator is charging battery
Check to see if the alternator is working Connect a voltmeter to battery: Without engine running reading should be about 12.8 With engine running reading should be 13.8-14.2 If not bad alternator
60 Amperes. And the question is properly phrased, "How much Current Output should the G20's alternator have?". "Amps" is not a word.
The alternator gauge, often found on the dashboard, indicates the charging status of the vehicle's battery. A reading in the positive range (usually marked as "charge" or "positive") means the alternator is supplying enough power to charge the battery, while a negative reading indicates the battery is discharging, which could signal a problem with the alternator or electrical system. Ideally, the needle should stay within the normal operating range during vehicle operation. If it consistently shows a negative reading, it's important to have the electrical system checked.