How to Test Car relay
Testing Car Relay Car Electric Control unit Wiring And Relay Testing Helpful Information A relay is switch that utilizes an electrical trigger signal to activate. Once activated the relay connects an electrical supply to a particular accessory. These accessories can range from the main computer PCM (powertrian control module), radiator fan, fuel pump, door locks etc. There are two tests that should be considered when dealing with a relay problem, is the problem with the relay itself or is the problem a power or ground issue. A relay is prone to failure when used for a long periods of time (hot) or when the amperage of the accessory has increased beyond its designed use. A rely should be considered as two separate halves, the primary side which utilizes an electromagnet to close the secondary electrical circuit. This electromagnet is activated by a simple power (+) and ground (-) much like a light bulb circuit. The second half of the relay is the "switch" that contro...