Technician Handbook 623 Electrical Circuit Diagnosis Current Current is the flow of electrons caused by electrical pressure. Voltage (electrical pressure) can exist without current flow. However, current cannot flow without voltage. Compare current to water flow. When a faucet is opened, water flows if there is water pressure. Without water pressure, there is no water flow. Current is measured in amperes , or “ amps ” for short. Current may also be referred to as “amperage.” Technical Training 9