15V
So for this one, system test, we can take a guess on what it means.
Knowing the tester was measuring at the battery, 14.8 Volts is probably close to alternator's output voltage.
The programming may be based on something where 14.8 V is low but for this car its not.
Then the tester added load drawing more current from the alternator.
The current to the tester flowed the same path that current would flow when the battery is charging. The ammeter should have moved toward charge.
There are at least two possible reasons why voltage at the battery dropped.
1. At idle speed the alternator couldn't produce enough power to run the ignition, the alternator, and supply the test load at 14.8 V.
2. There is some resistance in the wiring. Wherever current flows through resistance, voltage is reduced. Increasing current or increasing resistance will cause a greater drop in voltage.
Earlier in this thread there were suggestions about checking the voltage at the alternator output terminal against the voltage at the regulator input terminal. Excessive resistance between those two points is a common cause for high voltage.
Pretty cool.
So for this one, system test, we can take a guess on what it means.
Knowing the tester was measuring at the battery, 14.8 Volts is probably close to alternator's output voltage.
The programming may be based on something where 14.8 V is low but for this car its not.
Then the tester added load drawing more current from the alternator.
The current to the tester flowed the same path that current would flow when the battery is charging. The ammeter should have moved toward charge.
There are at least two possible reasons why voltage at the battery dropped.
1. At idle speed the alternator couldn't produce enough power to run the ignition, the alternator, and supply the test load at 14.8 V.
2. There is some resistance in the wiring. Wherever current flows through resistance, voltage is reduced. Increasing current or increasing resistance will cause a greater drop in voltage.
Earlier in this thread there were suggestions about checking the voltage at the alternator output terminal against the voltage at the regulator input terminal. Excessive resistance between those two points is a common cause for high voltage.