Decoding fuses and relays <em>Nissan Sunny</em>: diagrams, location and repair tips

Nissan Sunny is a legendary Japanese sedan that still remains popular among car owners due to its reliability and ease of maintenance. However, even such time-tested cars have electrical problems: the cigarette lighter stops working, the headlights fail, or the heater fan does not turn on. In 90% of cases it is to blame blown fuse or a faulty relay. But how to find them and replace them correctly?

In this article you will find full decoding of fuses and relays for Nissan Sunny generations B13 (1990–1995), B14 (1995–1998) And B15 (1998–2006), including photos of mounting blocks, layout diagrams and unique diagnostic tips, which are not in standard manuals. We will also look at common mistakes when replacing and tell you how to avoid short circuits when working with electrical equipment.

Where is the fuse box located in Nissan Sunny?

Depending on generation and configuration Sunny mounting blocks can be located in different places. In most cases there are two of them:

• 🔧 Main unit — under the hood, next to the battery (in models B13/B14 often hidden under a plastic cover).
• 🚗 Secondary block — in the cabin, under the dashboard on the driver’s side (on B15 maybe behind the glove compartment).
• ⚡ Additional relay - sometimes installed separately (for example, a fuel pump relay on Sunny GA15DE located under the rear seat).

On Nissan Sunny B13 (1990–1995) main fuse box is usually located to the left of the steering column, under the plastic panel. To open it, you need:

1. Unscrew the two panel mounting screws (screwdriver Phillips #2).
2. Carefully pry out the clips with a flat-head screwdriver.
3. Remove the unit cover by pulling it towards you.

On Sunny B15 (1998–2006) block moved under the hood, next to the battery. Its lid is secured with latches - just press them and pull up. Attention: mandatory before work disconnect the negative terminal of the batteryto avoid short circuit!

Explanation of fuses Nissan Sunny B13/B14 (1990–1998)

In models B13 And B14 used one mounting block with blade type fuses (size ATO/ATC). Below is a table with the purpose of each element. The numbers on the unit cover may not match the actual location - follow the diagram!

Fuse no.	Denomination (A)	Purpose	Symptoms of a problem
1	10	Interior lighting, instrument lighting, trunk lamp	The lamps do not light up, the panel backlight does not work
7	15	Cigarette lighter, audio system	The cigarette lighter does not heat, the radio does not turn on
10	20	Electric radiator cooling fan	Engine overheating, fan does not turn on
15	10	Direction indicators, hazard warning lights	Turn signals or hazard lights do not work
20	15	Engine control unit (ECU), fuel injectors	The engine stalls, does not start, is on fire Check Engine

⚠️ Attention: Fuse No. 20 (15A) responsible for nutrition ECU. If it burns out, the engine won't start, and the dashboard will light up Check Engine. Do not replace it with a fuse of a higher rating. - this can damage the control unit!

On Sunny B14 with engine GA16DE fuse added No. 25 (10A)responsible for immobilizer. If the car does not respond to the key or does not read the chip, check this element.

How to check a fuse without a tester?

If you don't have a multimeter at hand, you can visually inspect the fuse using light. Burnt out will have broken thread inside. You can also replace a suspicious fuse with a known good one with the same rating (for example, from the cigarette lighter circuit).

Decoding the relay in Nissan Sunny: where what and how to check

Relay in Sunny are responsible for turning on powerful consumers: starter, fan, headlights, etc. Unlike fuses, they don't burn out, but fail mechanically (contacts burn, coil breaks). Below is the location and purpose of the relay in the mounting block.

• 🔋 Starter relay - usually located separately, next to the battery. If there is a malfunction, clicks are heard, but the starter does not turn.
• 💨 Cooling fan relay — in the main block (position R2 on B13/B14). If it doesn't work, the engine overheats.
• 💡 Low/high beam relay — is responsible for the headlights. On B15 there may be two separate relays.
• 🔑 Ignition relay — if it breaks down, the car does not respond to turning the key.

To check the relay, you can:

1. Remove it from its socket and shake it - if something rattles inside, it is faulty.
2. Ring with a multimeter in mode diode continuity contacts 85 and 86 (coil). There must be resistance 50–120 Ohm.
3. Submit 12V to contacts 85 (+) and 86 (–) - there should be a click.

⚠️ Attention: On Nissan Sunny B15 relay cooling fan often fails due to oxidation of contacts. Before replacing, clean the unit slots alcohol solution and lubricate contact lubricant (For example, CRC 2-26).

Common electrical problems Nissan Sunny and their solutions

Owners Sunny often encounter repeated faults. Here are the most common:

• ⚡ The cigarette lighter fuse blows (No. 7, 15A) - usually a short circuit in the socket or a faulty connector is to blame. Solution: disassemble the cigarette lighter and check the carbon deposits on the contacts.
• 🔥 The generator circuit fuses melt (No. 11, 10A) - a sign of a faulty diode bridge. Solution: Check the generator on the stand.
• 🚨 Hazard alarm does not work - often the turn signal relay is to blame (R4) or oxidized contacts in the block.
• 🔋 The starter clicks but doesn't turn over - check the starter relay and power fuse (30A) under the hood.

If the fuse burns out immediately after replacement, this is a sign short circuit in the chain. Do not install a fuse of a larger rating. - this can lead to a fire in the wiring! Instead:

1. Disconnect all consumers in this circuit (for example, if the cigarette lighter fuse is on, disconnect the radio and chargers).
2. Test the wiring with a multimeter in callsto find short circuit.
3. Check the connectors for oxidation or melting.

On Sunny B15 with engine QG18DE often fails fuel pump relay (located under the rear seat). Symptoms: the car stalls while driving or does not start. Solution: replace the relay or check the power supply to the pump (12V on the pink wire).

How to correctly replace a fuse or relay in Nissan Sunny

Replacing a fuse seems like a simple procedure, but many car owners make mistakes that lead to serious damage. Follow this instruction:

1. Turn off the power — remove the negative terminal from the battery.
2. Find the faulty element - use the diagram from the previous sections.
3. Remove the fuse special forceps (available in the block cover) or tweezers. Do not use metal tools - the sockets can be damaged.
4. Install a new fuse same denomination. For example, instead of 10A can't bet 15A!
5. Check circuit operation — turn on the appropriate device (headlights, cigarette lighter, etc.).

To replace the relay:

1. Carefully remove it from the slot by pulling upwards.
2. Install a new relay same markings (there is a number on the case).
3. Check the fixation - the relay should fit tightly, without play.

⚠️ Attention: On Nissan Sunny B13/B14 there is one in the fuse box ignition relay (R1). If it is not installed correctly (upside down), the machine won't start. Focus on the marks on the body!

After replacing a fuse or relay be sure to check the circuit for leaks. If the problem recurs, look for the cause - perhaps somewhere frayed wiring or consumer shorts.

Where to buy fuses and relays for Nissan Sunny?

Original fuses and relays for Sunny can be found:

• 🛒 B auto parts stores (For example, Exist, Autodoc, Emex). Search by article:
  • Fuses: 28510-4M000 (ATO/ATC set).
  • Relay: 25230-4M000 (standard 4-pin).
• 🌍 On AliExpress or eBay - cheaper, but longer delivery. Search by request "Nissan Sunny B14 relay".
• 🔧 On showdown - if rare relays are needed (for example, for Sunny N16 with SR20DE).

When purchasing, pay attention to:

• Fuse rating - it is indicated on the body (for example, 10A, 15A).
• Relay type - on Sunny relays are used with 4 or 5 contacts (for fan).
• Manufacturer - reliable brands: Hella, Bosch, Valeo.

⚠️ Attention: Do not buy cheap fuses from unknown brands - they are often melt at lower currentthan indicated. For example, “15A” can burn out already at 10A, which will lead to false positives.

If you are not sure about the choice, take old fuse or relay take it with you to the store for comparison. There are usually markings on the case that will help you choose an analogue.

Frequently asked questions about fuses and relays Nissan Sunny

Why does it blow again after replacing the fuse?

This is a sign short circuit in the chain. Need:

1. Disconnect all consumers in this circuit.
2. Test the wiring with a multimeter to check for a short to ground.
3. Check the connectors and lamps - short circuits often occur due to melted cartridges.

On Sunny B14 common problem - short circuit in the wiring harness under the dashboard (insulation is frayed).

Where is the fuse for the radio?

On Nissan Sunny B13/B14 The radio is protected by a fuse No. 7 (15A) in the main block. On B15 there may be a separate fuse in the glove compartment (face value 10A).

If the radio does not work after replacing the fuse, check:

• Power on the yellow wire (+12V constant).
• The fuse is on the radio itself (sometimes it is built into the connector).

How to test the cooling fan relay?

Fan relay on Sunny can be checked in two ways:

1. Testing with a multimeter:
   • Set mode diode continuity.
   • Call contacts 85 and 86 - there must be resistance 50–120 Ohm.
   • Serve 12V on 85 (+) and 86 (–) - it should click.

Replacing with a known good one - take a relay from another circuit (for example, a turn signal relay) and install it instead of the one being tested.

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

• Temperature sensor (on the radiator).
• fuse No. 10 (20A).
• Wiring from relay to fan.

Is it possible to install a fuse of a higher rating?

Absolutely not! The fuse is designed for a certain current, and if you install a more powerful one (for example, 20A instead of 10A), this can lead to:

• Melting of wiring.
• Failure of the control unit (ECU).
• Fire in the cabin.

If a fuse constantly blows, look for the cause (short circuit or faulty consumer), and do not increase its rating!

Where is the starter relay located on Nissan Sunny B15?

On Sunny B15 starter relay located separate from the main unit - usually on left arch under the hood, next to the battery. It looks like a small box with 4 contacts.

If the starter does not turn, but clicks are heard, check:

1. Starter relay (replace with a known good one).
2. Power fuse 30A (can be hidden under the cover next to the battery).
3. Contacts on the starter solenoid relay.