Relays in Nissan Primera P12: where they are, how to check and replace

Nissan Primera P12 (2002-2008) is a reliable sedan, but even this has electrical components that fail over time. One of the common problems is relay, responsible for the operation of the headlights, cooling fan, fuel pump and starter. If your Primera P12 suddenly stopped starting, the engine gets hot or the headlights don’t come on - the relay may be to blame.

In this article we will analyze location of all relays in Nissan Primera P12, their purpose, symptoms of malfunction and step-by-step instructions for checking and replacing. You will also find a unique table with decoding of the relay by number and photo of the fuse box - this will help avoid diagnostic errors.

Where is the relay block located in Nissan Primera P12

B Primera P12 There are two main blocks with relays and fuses installed:

• 🔧 Main unit — located to the left of the steering column, under the plastic cover. To open it, pull the latch at the bottom of the panel.
• 🚗 Additional block — located in the engine compartment, next to the battery (under the black plastic cover). The relays for the cooling fan, fuel pump and starter are located here.

There is a diagram on the cover of the main unit with the designation of fuses, but relays are usually not signed. Their location depends on the configuration and year of manufacture. For example, in restyled versions (2005–2008), the relay unit may differ from the pre-restyling version (2002–2004).

To avoid guessing which relay is which, use table below or check the official manual Nissan Primera P12 (document code: EWM02P12).

Decoding relays in Nissan Primera P12 by numbers

The table below shows the standard relay numbering for most versions Primera P12. Please note: on some trim levels the location may differ (for example, in cars with climate control, the air conditioning compressor relay is added).

Relay number	Purpose	Location	Symptoms of a problem
R1	Starter relay	Additional block (engine compartment)	The starter does not turn, clicks when turning the key
R2	Fuel pump relay	Additional block (engine compartment)	The engine does not start, there is no pressure in the fuel rail
R3	Cooling Fan Relay (Low Speed)	Additional block (engine compartment)	The fan does not turn on, the engine overheats
R4	Cooling Fan Relay (High Speed)	Additional block (engine compartment)	The fan only runs at one speed
R5	Low beam relay	Main unit (lounge)	Both headlights or one lamp do not light up

If the relays are located differently in your car, check the diagram on the back of the unit cover or download the wiring diagram for your configuration. For example, in versions with xenon headlights relay is added R6 for light corrector.

⚠️ Attention: B Primera P12 with diesel engine YD22DDTi fuel pump relay (R2) can be duplicated - one in the engine compartment, the second in the cabin. Check both before replacing!

Signs of a relay failure in Primera P12

A relay is an electromechanical device that wears out over time. B Nissan Primera P12 Most often they fail:

• ⚡ Starter relay — the car does not start, clicks are heard, but the starter does not turn.
• 🔥 Cooling fan relay — the engine overheats, the fan does not turn on or runs constantly.
• ⛽ Fuel pump relay — the engine does not start, there is no pressure in the fuel system (check if the sound of the pump is heard when the ignition is turned on).
• 💡 Headlight relay — both headlights or one lamp do not light (if the lamp is working).

As a rule, relays are not repaired - they are only replaced. But before buying a new one, check:

1. Relay contacts for oxidation (clean them with alcohol or WD-40).
2. Wiring integrity (check with a multimeter).
3. The relay itself - sometimes it can be “reanimated” by lightly tapping (but this is a temporary solution).

If after checking the problem remains, the relay must be replaced. Cost of a new relay for Primera P12 - from 300 to 1500 rubles depending on the purpose.

How to check a relay in a Nissan Primera P12 with a multimeter

To test the relay you will need multimeter (or a simple 12 V light bulb) and a screwdriver. Follow the instructions:

1. Remove the relay from the block (remember its location!).
2. Look at the relay body - there should be a contact diagram there (usually 85, 86, 87, 30).
3. Connect the multimeter in dialing mode to the contacts 85 And 86 (coil). There must be resistance 50–120 Ohm. If there is a break, the relay is faulty.
4. Apply 12V to contacts 85 And 86 (possible from battery). You should hear a click, which means the coil is firing.
5. Call contacts 30 And 87 - in a closed state, the resistance should be close to 0 ohm.

If the relay does not click or there is no continuity between 30 And 87 - it needs to be replaced. For clarity, watch the video testing the relay Nissan:

Video instructions for checking the relay

There is a good video on YouTube from the Nissan Service DIY channel that shows the process of checking the fan relay on a Primera P12. Search query: "Nissan Primera P12 fan relay test with multimeter."

If you don't have a multimeter, you can use replacement method: Install a known good relay (for example, from the passenger compartment fuse box) and check if the problem goes away.

⚠️ Attention: Never test the relay for a spark - this may damage the control unit or other electronic components Primera P12!

Step-by-step relay replacement in Primera P12

Replacing the relay in Nissan Primera P12 takes 5–10 minutes. You will need:

• 🔧 Flat-head screwdriver (for removing the unit cover).
• 🔍 Flashlight (to better see the relay numbers).
• 🧤 New relay (preferably original Nissan or a high-quality analogue).

Instructions:

After replacing the starter relay or fuel pump, you may need to reset the errors ECU. To do this:

1. Disconnect the battery terminal for 10 minutes.
2. Plug it back in and start the car.
3. If it catches fire Check Engine, use a scanner (for example, ELM327) to reset errors.

If the problem remains after replacing the relay, check:

• 🔌 Fuses (they may blow due to a short circuit).
• 🔧 Wiring (especially in the engine compartment - wires often fray there).
• 📊 Sensors (for example, temperature sensor for a fan).

Common errors when working with relays in Primera P12

Many owners Nissan Primera P12 make mistakes that lead to repeated breakdowns or even fires in the wiring. Here are the most common:

• 🔥 Using relays from other models - even if it looks similar, the parameters may not match. For example, a fan relay from Nissan Almera N16 not suitable for Primera P12 due to different operating currents.
• 🔧 Incorrect installation - if the starter and fuel pump relays are swapped, the car will not start, and the starter may burn out.
• 💡 Ignoring contact oxidation - even a new relay will quickly fail if the contacts in the block are dirty.
• 📉 Buying cheap analogues - relays of unknown brands often fail. It's better to take the original (Nissan 25230-3M000 for the starter relay) or proven analogues (Hella, Bosch).

Another common mistake is checking the relay without removing it. For example, if you test a fan relay without disconnecting it from the unit, you may get false readings due to parallel circuits.

If after replacing the relay the problem returns after some time, look deeper for the cause:

• 🔋 Check it out battery - low voltage (less than 11.5 V) may cause false relay activations.
• 🔌 Take a look mass — poor contact with the body leads to unstable operation of the electronics.
• 📊 Diagnose ECU — the control unit may give incorrect signals to the relay.

Where to buy a relay for Nissan Primera P12 and how much does it cost

Relay for Primera P12 can be purchased at the following places:

Place of purchase	Cost (RUB)	Pros	Cons
Official dealer Nissan	1200–2500	Warranty, original parts	Expensive, long wait
Online stores (Exist, Autodoc, Kolesa-darom)	300–1500	Fast delivery, large selection	Risk of running into a fake
Auto parts market	200–1000	Low price, you can bargain	No warranty, often used parts
Showdown	100–500	Very cheap	Relay may be worn out

When purchasing, pay attention to:

• 📌 Article - original relays for Primera P12 have numbers like 25230-XXXX.
• 🔍 Appearance — there should be no cracks, melting or signs of corrosion on the body.
• 📄 Guarantee — good stores give a guarantee of 6 months.

If you are buying a relay for cooling fan, take two at once - for low and high speed (they often fail in pairs).

FAQ: Frequently asked questions about relays in Nissan Primera P12

Can the relay be repaired or just replaced?

The relay is a non-repairable part. In rare cases, cleaning the contacts helps, but if the coil or contacts inside are burnt, just replace it. Attempting to solder a relay usually results in a short circuit.

Why does the starter relay click but the starter does not turn?

This may be caused by:

• 🔋 Discharged battery (voltage below 11 V).
• 🔌 Poor contact on the starter or relay terminals.
• 🔧 Wear of starter brushes (need to be disassembled and checked).

First check the battery charge and contacts, then test the starter.

Which relay is responsible for the cigarette lighter in Primera P12?

B Primera P12 cigarette lighter protected fuse (not a relay) on 15 A, which is located in the main block (salon). Designation: F18 (for versions 2002–2004) or F20 (for 2005–2008).

Is it possible to install a relay with a higher current than the original?

No! If you place a relay with a current higher than the original (for example, 30 A instead of 20 A), this can lead to:

• 🔥 Overheating of the wiring.
• 💥 The control unit has failed.
• ⚡ Short circuit.

Always use a relay with the same parameters as the original.

Where can I find the relay diagram for my version of Primera P12?

The diagram can be found:

1. On the back of the fuse box cover.
2. In the official manual (Nissan Primera P12 Service Manual).
3. On owner forums (for example, Nissan Club Russia or Drive2).

If you are not sure, take a photo of the block and ask on the forum - they will tell you the decoding.