Ammeter voltage drop
Voltage drop in the wiring can also be measured directly.
With no current flowing, there can be no voltage drop.
For example if the battery has 12.8 Volts, the voltage at the alternator's output terminal better be the same.
Measuring directly looks like this.
If you want to measure resistance for hunting really poor connections or broken circuits.
Disconnect the battery, set the meter to ohms, and check this will indicate major problems in the wiring between the probes.
If all that checks out, then go on to measuring voltage drop by putting a load on the circuit.
For example to check the line from the battery positive to the main splice, with the engine off, turn on the parking lights and headlights.
About 12 amps will flow through the wires.
If the meter shows 0 Volts, that portion of the circuit highlighted is pretty good.
Voltage drop in the wiring can also be measured directly.
With no current flowing, there can be no voltage drop.
For example if the battery has 12.8 Volts, the voltage at the alternator's output terminal better be the same.
Measuring directly looks like this.
If you want to measure resistance for hunting really poor connections or broken circuits.
Disconnect the battery, set the meter to ohms, and check this will indicate major problems in the wiring between the probes.
If all that checks out, then go on to measuring voltage drop by putting a load on the circuit.
For example to check the line from the battery positive to the main splice, with the engine off, turn on the parking lights and headlights.
About 12 amps will flow through the wires.
If the meter shows 0 Volts, that portion of the circuit highlighted is pretty good.
