Honda 39794-SDA-902 Relay Assembly, Engine Control Module (Denso)

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Some of the electrical feature in the pne we have the fuel injection system, horns, starter, and the fog lamps among others, use relays to convey electrical signals to the various parts. Relays have a low current control circuit to switch ON/OFF a high current power circuit; if a relay fails, the related component will be ineffective. Apart from engine and interior fuse/relay boxes, most relays are situated and if suspect output relay is sensed, it must be pulled out and tested through a procedure or be referred to a dealer service or a repairer shop to be replaced in case the relays are defective they must be replaced as a single unit. The general relays employed are the ISO relays with terminals marked with numbers to show the circuits and their roles, and are categorized by two terminal configurations. The control circuit terminates on the coil while the terminals of the power circuit are connected to the coil. When energized, the coil produces a magnetic field to make the larger contact of the power circuit to close in order to allow the circuit loads to be supplied with power. In most cases, the two terminals 85 and 86 constitute the control circuit; however, if there is a diode, terminal 86 is connected to the battery positive voltage and the terminal 85 to the ground; if there is only a resistor terminal 85 and terminal 86 may be connected in either direction. Terminal 30 is mainly associated with the battery voltage supply for circuits and terminal 87 is associated with the ground of the circuit. In order to verify the relay, an ohmmeter can be used in testing-making sure to connect the meter according to the polarity-and reversing the leads to give a second test on the continuity of the relay control coil. This is because, if a resistor is present it must have equal resistance whether in reverse or forward use, while a diode shall have relatively high resistance to the forward use as compared to the reverse use. When there is an infinite resistance in both directions, then it is recommended that the relay be substituted. After removing the relay, there should be no continuity between two terminals of the power circuit, and the capacitor should not remain connected when capacitive or inductive loads are switched off, so there will be no continuity between terminal 30 and 87 when de-energised. By touching one end of the fused jumper wire at terminal 86 and other end to positive terminal of the battery and another jumper wire to terminal 85 to ground, the relay should emit a clicking sound. Once the jumper wires are connected, continuity should be present in between terminals 30 and 87. Any relay not passing these tests should be replaced.

Many electrical accessories, such as the fuel injection system, horns, starter, and fog lamps, utilize relays to control current to components.

Most relays are typically mounted in the engine compartment and interior fuse or relay boxes.

Most relays are typically mounted in the engine compartment and interior fuse or relay boxes.

If a relay is defective, the components powered by it will not operate, and defective relays must be replaced as they cannot be repaired.

Relays function by allowing a low-current control circuit to open and close a high-current power circuit.

A defective relay will prevent the components powered by the high-current circuit from functioning.