You can disconnect the electrical harness connector for the circuit being tested, if necessary, enable the circuit and/or system being tested, select the V (AC) or V (DC) position on the DMM, connect the positive lead of the DMM to the point of the circuit to be tested, connect the negative lead of the DMM to a good ground, then the DMM displays the voltage measured at that point.
By BobGM Specialist
29/10/2022