Cooling fan relay <em>Nissan Almera</em>: how to identify the malfunction and fix it yourself

The engine cooling fan is a critical element of the thermal management system. Nissan Almera, and its failure can lead to overheating of the engine, deformation of the cylinder head and even major repairs. One of the most common reasons for a non-working fan is failure switching relay. This small part, costing from 300 to 1500 rubles, can paralyze the operation of the entire cooling system if attention is not paid to it in time.

In this article we will look at how diagnose the fan relay on Almera N16, G15 And Classic, where it is located in the fuse box, what tools are needed for replacement, and why sometimes the problem lies not in the relay itself, but in the temperature sensor or wiring. You will also learn how to temporarily start the fan bypassing the relay - this can save the engine in an emergency.

Symptoms of a bad fan relay Nissan Almera

The first signal about problems with the relay is the fan stops turning on when the engine warms up to operating temperature (90–95°C). However, this is not the only symptom. Here is a complete list of signs that should alert you:

• 🔥 Fan doesn't start at all, even when the engine is idling for a long time in the heat.
• ⚡ The fan is running constantly, regardless of the engine temperature (the relay is “stuck” in the closed state).
• ⚠️ The dashboard lights up CHECK ENGINE or an overheat indicator, but no other causes (antifreeze leak, faulty thermostat) were found.
• 🔄 The fan turns on delayed or works jerkily - this may indicate burning of the relay contacts.
• 💥 When you turn on the fan you can hear clicking sounds from the fuse box (characteristic sound of a faulty relay).

It is important to distinguish a relay failure from other cooling system malfunctions. For example, if the fan does not work due to wiring break or failure temperature sensor, replacing the relay will not help. To accurately determine the culprit, you will need diagnostics - we’ll talk about it further.

⚠️ Attention! If the fan does not turn on when the temperature is above 100°C, and you continue to drive, the risk of engine overheating increases significantly. In such a situation stop immediately, turn off the engine and wait until it cools down. Operation Almera with a non-working fan is fraught with deformation of the cylinder head and repairs costing tens of thousands of rubles.

Where is the fan relay located? Nissan Almera (N16, G15, Classic)

The location of the relay depends on the generation and year of manufacture Almera. In most cases it is in fuse and relay box under the hood or in the cabin. Below are the exact coordinates for different modifications:

Model Nissan Almera	Year of manufacture	Relay location	Number in block
Almera N16 (1.5/1.8)	2000–2006	Fuse box in the passenger compartment (under the steering wheel, on the left)	Relay No. 3 (or No. 5 on some versions)
Almera Classic (B10)	2006–2012	Unit under the hood (next to the battery)	Relay No. 2 (next to fuse F20)
Almera G15 (new generation)	2012–2018	Unit in the cabin (under the instrument panel, driver's side)	Relay No. 4 (labeled "RADIATOR FAN")

To get to the fuse box in the passenger compartment, you will need:

1. Open the driver's door and move the seat back.
2. Press the latch of the unit cover (usually located at the bottom of the instrument panel).
3. Remove the cover and find the relay by number or inscription (on some units there is a diagram on the back of the cover).

On Almera Classic The block under the hood is covered with a plastic cover. To remove it, pull the latches on the sides. The fan relay is usually located near fan fuse (nominal 30–40 A).

How to test the cooling fan relay: step-by-step instructions

Before replacing the relay, you need to make sure that it is the problem. This will require multimeter (or control lamp) and minimal skills in working with electrical equipment. Follow the algorithm:

1. Remove the relay from the block (gently pull it up without applying excessive force).
2. Inspect the contacts for oxidation, burning or melting. If the contacts are blackened, the relay must be replaced.
3. Ring the winding:
   • Set the multimeter to 200 Ohm.
   • Connect the probes to the terminals 85 And 86 (winding contacts).
   • Resistance must be within 50–120 Ohm. If the device shows 1 (break) or 0 (short circuit) - the relay is faulty.
4. Check the functionality of the contacts:
   • Connect 12 V to conclusions 85 And 86 (polarity is not important).
   • Multimeter in mode 200 Ohm check the resistance between 30 And 87.
   • When voltage is applied, the resistance should drop to 0 ohm (the contacts will close). If this does not happen, the relay is not working.

If the relay is OK, but the fan does not work, check:

• 🔌 Fan fuse (usually 30–40 A, located next to the relay).
• 🌡️ Coolant temperature sensor (located on the thermostat or radiator).
• 🔌 Wiring from the relay to the fan (contact breakage or corrosion is possible).

Remove the relay from the block|Inspect the contacts for burnt|Ring the winding (85–86)|Apply 12 V and check the circuit (30–87)|Check the fuse and temperature sensor-->

⚠️ Attention! Do not confuse the fan relay with air conditioner relay or fuel pump relay - they may have a similar appearance, but different purposes. The reverse side of the relay is usually marked (for example, RAD FAN or COOLING FAN).

Replacing the fan relay with Nissan Almera: detailed instructions

If the diagnostics confirm that the relay is faulty, it must be replaced. For this you will need:

• 🔧 New relay (analogous to the original one: 25230-31U00 for N16, 25230-4M000 for Classic/G15).
• 🔧 Flat screwdriver (for removing the block cover).
• 🔧 Multimeter (for re-checking after installation).

Procedure:

1. Disable negative battery terminal (this will prevent short circuit).
2. Remove the fuse box cover (in the passenger compartment or under the hood, depending on the model).
3. Locate the faulty relay and carefully remove it by pulling it up. If the relay is stuck, pry it off from the side with a screwdriver.
4. Install a new relay same markings. It is important that the contacts match in location!
5. Replace the unit cover and connect the battery.
6. Start the engine and warm it up until the fan turns on (or force the temperature sensor contacts to check).

If after replacing the relay the fan still does not work, the problem may lie in:

• 🔌 Broken wiring between the relay and the fan.
• 🌡️ Faulty temperature sensor (it sends a signal to the relay).
• 🔋 Oxidized contacts on the fan connector.

Temporary solution: how to start the fan bypassing the relay

If the relay fails on the road and you don’t have a new one at hand, you can force the fan onby closing the contacts in the fuse block. This is a temporary measure, but it will help you get to the service without the risk of overheating.

Instructions for Nissan Almera N16/Classic/G15:

1. Remove the fan relay from the unit.
2. Find the contacts on the block 30 (supply +12 V) and 87 (fan output).
3. Paste into these contacts jumper (you can use a paper clip or a piece of wire).
4. The fan must turn on immediately for a permanent job.

⚠️ Important! In this mode the fan will work continuously, even on a cold engine. Therefore:

• 🚗 Use this method only for getting to the service.
• 🔌 After stopping be sure to remove the jumper, otherwise drain the battery.
• 🌡️ Monitor the motor temperature - if the fan does not turn on, the problem may be in the fan motor itself.

What happens if you drive with the fan relay closed?

With constant fan operation, the load on the generator and battery increases, which can lead to their premature wear. In addition, the fan creates additional air resistance, slightly increasing fuel consumption (by 0.2–0.5 l/100 km). However, the main danger is masking real problems: If the fan is running constantly due to a faulty temperature sensor, you may not notice the overheating until it's too late.

Frequent mistakes when diagnosing and replacing relays

Even experienced car owners sometimes make mistakes that complicate repairs or lead to repeated breakdowns. Here are the most common of them:

• 🔧 Buying the wrong relay. For example, instead of a fan relay, a headlight or air conditioning relay is installed. These relays may have the same housing, but different load capacity (the fan consumes up to 20–30 A, and the turn signal relay consumes only 5–10 A).
• 🔌 Ignoring the fuse. If the fan fuse is blown, replacing the relay will have no effect. Always check F20 or F25 (the value is indicated on the block cover).
• 🌡️ Untested temperature sensor. If the sensor produces incorrect data, the relay will not receive a signal to turn on. You can check the sensor by closing its contacts - the fan should turn on.
• 🔋 Contact corrosion. Oxidized or burnt contacts in the fuse box may prevent the relay from operating properly. Clean them up alcohol solution or fine sandpaper.

Another common mistake is relay test without load. For example, some car owners simply listen to the relay click when voltage is applied, but do not check whether the power contacts are closed (30–87). The click only indicates that the winding has been activated, but does not guarantee that the current will pass further.

Relay cost and where to buy it: original vs analogues

Fan relay price for Nissan Almera varies depending on type and manufacturer:

Relay type	Manufacturer	Article	Price, rub.	Notes
Original	Nissan	25230-31U00 (N16)	1200–1800	Guaranteed quality, but high price
Analogue	Bosch	0 332 014 150	400–600	Reliable option, suitable for most models
Analogue	Hella	4RA 007 507-331	500–800	Good quality, but sometimes there are fakes
Budget	ERA	550109	250–400	Low price, but the resource is less than the original

Where to buy:

• 🛒 Official dealers Nissan - original parts, but expensive.
• 🛒 Online stores (Exist, Autodoc, Kolesa.ru) - a wide selection of analogues at low prices.
• 🛒 Auto parts markets - cheaper, but there is a high risk of running into a fake.
• 🛒 Showdown - a used relay for 100–300 rubles, but without a guarantee.

Important: on Nissan Almera G15 (2012-2018) The fan relay is often included with the A/C relay. When purchasing, check whether the part is suitable for your modification (gasoline/diesel, engine size).

FAQ: Frequently asked questions about the fan relay Nissan Almera

❓ Is it possible to drive without a fan relay if the contacts are closed?

Technically yes, but this extremely dangerous. The fan will run constantly, which will lead to:

• Rapid battery discharge (especially during short trips).
• Increased load on the generator.
• Risk of overheating if contacts are not closed correctly.

Use this method only for getting to the service!

❓ Why does the fan turn on when the engine is cold?

This is a typical sign relay sticking in a closed state. Reasons:

• Burning of contacts inside the relay.
• Short circuit in control circuit.
• Temperature sensor malfunction (constantly sends a signal to turn on).

Solution: Replace the relay and check the temperature sensor.

❓ Which relay can be used instead of the original one?

Analogues with the same characteristics are suitable:

• Rated voltage: 12 V.
• Maximum current: not less than 30 A.
• Contact type: Normally open (NO).

The best analogues: Bosch 0 332 014 150, Hella 4RA 007 507-331.

❓ How to check the temperature sensor if the relay is working properly?

Verification methods:

1. Remove the connector from the sensor and close the contacts jumper. If the fan turns on, the sensor is faulty.
2. Check the sensor resistance with a multimeter:
   • On a cold engine: ~3–5 kOhm.
   • Hot (90°C): ~200–300 Ohm.

❓ Why does the new relay burn out quickly?

Reasons for repeated failure:

• 🔥 Short circuit in the fan circuit (check the wiring).
• 🌡️ Faulty temperature sensor, giving false signals.
• 🔋 Weak grounding fuse box (check ground).
• 💧 Moisture ingress into the fuse box (for example, after washing).