Checking A Voltage Drop

Testing Methods: Checking A Voltage Drop:

This method is used to ascertain whether the voltage drop in a wiring harness or across a component, etc., is too high.
1. Connect the voltmeter's positive lead to that part of the cable or component closest to the power supply.
2. Connect the voltmeter's negative lead step by step towards the load (item of electrical equipment), which should be switched on.
3. When the circuit is activated, i.e. when current flows through it, the voltmeter will show the difference in voltage between the two measurement points.

A circuit in perfect working order should not show a voltage drop of more than about 1V.

In simple circuits or connectors, the voltage drop ought not to exceed about 0.5 V.