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How do I know if my main relay is bad?

How do I know if my main relay is bad?

Symptoms of a Bad or Failing Main Relay (Computer/Fuel System)

  1. The engine will not start. Most car owners take their engine for granted until there is an issue with it.
  2. The car can’t stay running for long periods of time.
  3. The Check Engine Light is on.

Where is the main relay on a 1992 Honda Accord?

The main relay controls the fuel pump, it is right above the hood release lever on the side of the car under the dash. Unplug the 8-pin plug from it. You could also remove the bottom cushion of the back seat, remove access panel, and unplug the harness from the fuel pump there.

What is the main relay?

The main relay is a device that opens and shuts the fuel system, and in most cars it also opens and shuts the ignition system. A common main relay problem is that the car doesn’t start if the interior of the vehicle gets hot. This joint causes main relay problems in cars.

How do you test a Honda main relay?

How to Test the Main Relay in a Honda

  1. Consult your owner’s manual or vehicle repair manual and remove the main relay.
  2. Attach the battery positive terminal to the No. 4 terminal and the battery negative terminal to the No.
  3. Attach the battery positive terminal to the No.
  4. Attach the battery positive terminal to the No.

What causes a main relay to fail?

Even in low-level signal applications, accidents and faulty UUTs can cause relay failures, and inrush currents, caused by hot-switching capacitive loads, and voltage spikes, caused by hot-switching inductive loads, accelerate relay aging. Below are examples of failed relays.

Where is the main relay on a 2004 Honda Accord?

It’s mounted in the interrior fuse box inside the car.

What happens when the ignition relay goes bad?

If the relay fails it will cut off power to fuel pump and ignition system, which will result in a no power, and therefore no start condition. You may find that turning the key may power on the accessories, and may even crank the engine.

Will a bad main relay cause no spark?

If the fuel pump does not prime AND there is no spark, then it could be a bad main relay, a blown main relay fuse or ECU fuse, or a bad ground connection on the thermostat housing. If you only lack spark, check the timing belt and the coil and igniter unit in the distributor.

Will a bad relay still click?

If you hear or feel the relay click, the relay and its wiring aren’t the problem. But if it’s not clicking, the problem could be in the relay itself or in the wiring. Actually, unless the relay has a diode in it, it won’t matter if the polarity is switched; the electromagnet will be energized regardless.

What comes first fuse or relay?

3 Answers. The fuse should always be the first thing a power supply hits when it gets to a circuit. The reason is pretty simple. In the event of a fault that blows the fuse, the power is isolated to where it entered the circuit, thus the whole circuit is protected.