Ford F5TZ-14N089-B Relay

Fuel injection system, horns, starter and fog lamps in the vehicle employs relays to switch electrical signals to the respective units. Relays use a lowcurrent control circuit to control a high current power circuit and if a relay is bad then the associated component will not work as it is supposed to. Majority of the relays are placed at the engine compartment fuse/relay box while some specific relays are placed on top of the interior fuse box in the dash. The fuse block is located at the back of the bus but to get there, one has to remove the fuse panel cover which is underneath the steering column. If a faulty relay is thought to be present, it may be removed and examined by following a particular course of action or by taking the vehicle to a dealer service department or a repair shop; yards defective relays are rectified as a unit. More often than not, relay's terminals are labeled in numbers according to ISO standards whereby they communicate the circuits and functions of the particular relay. Among the mentioned terminals four of them are control terminals which are connected to the relay control circuit and interacts with the relay coil while the rest are power terminals. When energized, the coil produces a magnetic field and this closed the larger contacts of the power circuit hence supplying power to the circuit loads. Terminals 85 and 86 are usually for the control circuit, certain connections are needed if a diode or resistor is present. Terminal 30 provides connection to the battery voltage most often used on the circuit loads, while terminal 87 connects the ground side of the circuit. For testing relay continuity ohmmeter can be used for continuity check through relay control coil, and then check its appropriate resistance and continuity at the power circuit terminals. This terminal can be connected to Terminal 86 and the positive terminal of the battery; the other wire connecting Terminal 85 to ground to make the relay click. Continuity should then be checked between the power circuit terminals and also ensuring that it functions properly if any test does not work as required then the relay should be replaced.

Several electrical accessories in the vehicle, such as the fuel injection system, horns, starter, and fog lamps, use relays to transmit electrical signals to the components. Relays operate a low-current control circuit to open and close a high-current power circuit, and if a relay is defective, the associated component will not function properly. Various relays are mounted in the engine compartment and throughout the vehicle, and if a faulty relay is suspected, it can be removed and tested or taken to a dealer service department or repair shop, with defective relays needing replacement as a unit. To test a relay, it's helpful to consult the wiring diagram for proper hook-ups; however, if that's not possible, the following information can assist. Most relays have two terminals for the control circuit, which connect to the relay coil that, when energized, closes the large contacts to complete the circuit, while the other terminals are for the power circuit, which connect internally when the control circuit coil is energized. Relays are typically marked to help identify the control and power circuit terminals. To test, remove the relay and check for continuity between the power circuit terminals, ensuring there is no continuity between terminal 30 and 87. Next, connect a fused jumper wire from one control circuit terminal to the positive battery terminal and another from the other control circuit terminal to ground; the relay should click. If it doesn't, polarity may be critical, so swapping the jumper wires may be necessary. With the jumper wires connected, check for continuity between the power circuit terminals, which should now show continuity between terminals 30 and 87. If the relay fails any of these tests, it should be replaced.

It is necessary to switch off the ignition switch and the corresponding electrical circuit if one wishes to remove any fuses or relays and the battery ground lead must be disconnected if anything electrical must be disconnected. Switches are made to break a circuit when a given current value is reached in order to avoid damaging a circuit in question, various components, and wiring due to excess current, usually as a result of a fault such as short circuit. The main central fuse box, which also contains some relays, is situated inside the car at the left end of the instrument panel beneath and to the left of the steering column and is marked by a removable cover. There is a combined timer relay at the rear of the primary fuse-box which operates the heated rear window, rear luminaries, and arranged wiper operation; it also triggers an alarm bleep in case the lights are left ignited or an automatic transmission car is poorly parked. The auxiliary fuse box is located on the right hand side of the firewall in the engine compartment behind the air cleaner which one has to open to access and there are few relays too. The circuits are numbered on the main fusebox: and on the inner lid of the auxiliary fusebox there are writings and wiring diagrams showing the circuits covered by the corresponding fuse. To check the fuses you must use a test light, if the light begins to glow from the exposed terminal ends, that fuse is bad, in addition the element between the terminals gives it away. Never use a higher capacity fuse or a piece of wire to patch up a fuse; this can cause significant harm or fire; it's printed on the top of a fuse. This is in addition to a 'battery saver' relay for the central fusebox in the event that the car is to be off the road for a long time. Some of the parts such as relays might be electrically operated switches used in certain circuits; these can be removed by simply pulling them from their sockets and some are fitted with a plastic bar which makes them easier to pull using the tweezers. When a relay-controlled component becomes a problem, listen closely when the circuit is turned on; if the relay makes a clicking sound, the relay is okay; the problem is elsewhere. If the relay does not energize, it may be because the relay is not getting switching voltage or is dead and the testing can be done by swapping the suspected relay with a known good relay, though different relays looking alike may do different things.

To test for continuity between the relay power circuit terminals, remove the relay from the vehicle and use an ohmmeter. There should be no continuity between terminal 30 and 87 with the relay de-energized.

If the relay fails any of the above tests, replace it.

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

If the relay fails any of the above tests, it should be replaced.

If the relay is defective, the component it controls will not operate properly.

If the relay contains a resistor, the resistance will be indicated on the meter and should be the same value in either direction.

Two of the terminals are for the relay control circuit, connecting to the relay coil, while the other terminals are for the power circuit. When energized, the coil creates a magnetic field that closes the larger contacts of the power circuit.

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

Remove the relay from the vehicle and use the ohmmeter to check for continuity between the relay power circuit terminals. There should be no continuity between terminal 30 and 87 with the relay de-energized.

Relays use a low-current circuit (the control circuit) to open and close a high-current circuit (the power circuit).

On most relays, two terminals are for the control circuit (connected to the relay coil) and the other terminals are for the power circuit (connected together when the control circuit coil is energized).

If a relay fails any of the tests mentioned above, it should be replaced.

The relay center contains the air conditioning WOT cutout relay, fuel pump, PCM power relay, and PCM power diode.