Q: What is the general information about relays on 2003 through 2009 Toyota 4Runner?
A: In the vehicle, other electrical accessories include, the fuel injection system; the starter motor, the fog lamps; all of which use relays to switch electrical signals to them. Relays work on a low current control circuit for a high current power circuit and any bad relay will not enable the right action of the related component. Majority of the relays are in the engine compartment fuse/relay boxes and there are some limited relays above the interior fuse box in the dashboard. If a faulty relay is purported, then it has to be removed and tested, either following a certain process or taken to a dealer service department or a repair shop and since relays are sold and distributed as complete assemblies, deteriorated relays have to be replaced in their entirety. The four types of relays used are; there are types which are normally closed and there is current passing through one circuit till is gets tripped and breaks that circuit and closes another one. Conventionally, two of the terminals are used for the relay control circuit that connects towards the relay's coil while the other terminals connect to the power circuit that is internally connected when the control circuit is energized. Controlling and power circuit terminals of some relays may be marked and if not, wiring diagrams can help in determining the right wiring. When testing a relay, an ohmmeter should be connected between the power circuit terminals expecting the circuit to have no continuity. For a rather conventional 'four-terminal', normally open relay, it should have continuity when energized and should not have continuity when de-energized. One of the terminals of the control circuit should be fused to the positive terminal of the battery and the other terminal of the control circuit should be fused to ground; on closing the relay there should be a clicking sound and there should be continuity when measured on the meter. If the relay does not click, it will be require the jumper wires be switched. If the relay does not work as expected each time it is given as a test, it should be replaced.
Q: What is the general information about relays and their testing on 2005 through 2009 Toyota Tacoma?
A: Some of the other components in the automobile that has relays include fuel injection systems, horns, starter, as well as fog lamps. Relays consist of a low current control circuit and high current power circuit; an improper relay will hinder the work of connected component. Majority of the relays are usually placed at the fuse/relay boxes in the engine compartment though, some special relays can be placed above the interior fuse box near the dash board. Again, if a faulty relay is suspected, it can be removed and tested either through a special procedure or any dealer service department or any repair shop and the relay if found, to be defective must be replaced as a unit. There four different types of relays that are used, these include normally open; normally closed; and certain types of relays that, when energized, also close multiple circuits. Usual two terminals are control circuit and connected to the relay coil while the other two terminals are power circuit. Some relays may be marked to help in the identification of the control and power circuit terminal. To check a relay an ohmmeter should be connected between the terminals of power circuit and no continuity should be observed. In a normal situation for a relay with four terminals 'NO' there must be continuity in the circuit when the circuit is energized and no continuity in the circuit when the circuit is de-energized." A fused jumper wire shoud be connected between one of the control circuit terminal and the positive terminal of the battery, and another jumper wire connected between the other control circuit terminal and the ground: the relay should make a click and the continuity of the load should be indicated on the meter. Swapping the jumper wires may be needed if the relay does not click in this case. If the relay in question does not respond to any of these tests, it should be replaced.