Fuses and relays <em>Nissan Sunny FB15</em> (2011–2017): location, diagrams and decoding

Nissan Sunny FB15 is a popular sedan released in 2011–2017 for the markets of Asia, the Middle East and Latin America. Despite the simplicity of the design, the electrical equipment of the car requires attention, especially when it comes to fuses and relays. Failure of even a small component can result in non-functioning headlights, brake lights or engine control unit. In this article we will look at where the fuse boxes are located in Sunny FB15, how to properly check and replace them, and also consider typical electrical problems.

The main difficulty for owners is the lack of uniform documentation in Russian. Many fuse diagrams in the manuals are given in English or Japanese, and the numbers and assignments of the elements may differ depending on the configuration. We systematized the data, added photographs of real blocks and compiled tables with a breakdown of each fuse and relay. You will also learn how to avoid common diagnostic mistakes and why The fuse is not always to blameif the device does not work.

Where are the fuse boxes located in Nissan Sunny FB15

B Sunny FB15 There are two main fuse and relay blocks:

• 🔧 Main unit in the cabin — located to the left of the steering column, behind the protective cover. This is where the fuses for most systems are concentrated: lighting, audio, climate control and electronics.
• 🚗 Additional block under the hood — located next to the battery, in a plastic box. Responsible for high-voltage circuits: starter, generator, cooling fans and fuel pump.

Also in some configurations may be present third block — it is located behind the glove compartment and is responsible for additional equipment (for example, heated seats or a rear view camera). However, in basic versions FB15 it usually isn't.

To gain access to the interior unit, just pull the cover towards you (it is secured with latches). In the engine compartment, the cover is attached to two plastic clips - they need to be carefully snapped off with a screwdriver so as not to break them.

Diagram and decoding of the cabin unit fuses

Salon block Nissan Sunny FB15 contains 10–30 A fuses responsible for low-voltage circuits. Below is a table with the purpose of each element (the numbers correspond to the markings on the block cover).

Fuse no.	Denomination (A)	Purpose	Notes
1	10	Audio system, navigation	Also responsible for the USB port and Bluetooth module
5	15	Cigarette lighter	Often burns out when connecting powerful devices (for example, a compressor)
10	20	Window lifters	If all the windows do not work, check the relay K5 in the same block
14	10	Dashboard lighting	When burned out, the speedometer backlight dims or flashes
20	15	Engine control unit (ECU)	Replacing this fuse requires an error reset via the diagnostic scanner.

Particular attention should be paid to the fuse №20 (ECU). If it burns out, the engine may stall or go into limp mode. In this case, a simple replacement is not enough - you will need to reset errors via OBD-II (for example, using ELM327).

⚠️ Attention: Never install a fuse with a higher rating than indicated in the table! For example, instead of 10 A, you cannot install 15 A - this can lead to a fire in the wiring.

Engine compartment fuse and relay box: what is where

Engine compartment block Sunny FB15 contains more powerful fuses (up to 100 A) and relays responsible for critical systems. Its location is next to the battery, under a black plastic cover. Important: before working with this block Be sure to remove the negative terminal from the batteryto avoid short circuit.

Below are the key elements of the engine compartment:

• ⚡ Fuse 40 A (F1) — main fuse of the power circuit. When it burns out, the car is completely de-energized.
• 🔥 Fuse 30 A (F7) — fuel pump. If the car does not start, but the starter turns, check this element.
• 🌀 Relay K3 — cooling fan. If it malfunctions, the engine overheats.
• 🔋 Relay K8 — generator. If it fails, the battery will not charge.

One of the most problematic elements is Cooling Fan Relay (K3). If it fails, the fan does not turn on, which leads to overheating of the engine. Symptoms: the temperature arrow creeps into the red zone, but the fan does not make noise. Check the relay by replacing it with a known good one (for example, with K5, if it is the same type).

Check fuse F4 (10 A) in the engine compartment|

Swap relays K3 and K5 (if the fan starts working, K3 is faulty)|

Test the circuit with a multimeter (winding resistance should be 50–120 ohms)|

Inspect the temperature sensor connector (may be oxidized)

-->

Common fuse problems and how to avoid them

Owners Nissan Sunny FB15 often encounter repeated blown fuses. This indicates a more serious problem in the electrical circuit. Let's look at the most common cases:

1. The cigarette lighter fuse (15 A) blows when connecting devices.

   Reason: use of non-standard gadgets (compressors, inverters) with a current consumption higher than 15 A. Solution: connect powerful devices directly to the battery through a fused splitter.

2. The power window fuse (20 A) fails after rain.

   Reason: moisture ingress into the window lifter mechanism or contact oxidation. Solution: remove the door trim, dry the mechanism and treat the contacts WD-40.

3. The ECU fuse (15 A) blows for no apparent reason.

   Cause: a short circuit in the wiring harness under the dashboard or a malfunction of the control unit itself. Solution: diagnostics at a service station with checking the circuit with a multimeter.

If the fuse blows immediately after replacement, do not try to place an element of a higher value - this may cause a fire. Instead:

• 🔍 Check the circuit for a short circuit with a multimeter (testing mode).
• 🛠️ Inspect the connectors for oxidation or melting.
• 📋 Consult an electrician if you cannot find the cause on your own.

How to properly check and replace fuses

Checking the fuses in Nissan Sunny FB15 does not require special skills, but there are nuances that will help you avoid mistakes. Here are the step-by-step instructions:

1. Turn off the power.

   For the interior unit, simply remove the key from the ignition. For the engine compartment, remove the negative terminal from the battery.

2. Remove the fuse.

   Use plastic tweezers (usually attached to the lid of the unit). If it is not there, you can carefully pry the fuse off with a screwdriver.

3. Check visually.

   A blown fuse has a burnt or torn link. Sometimes the damage is not visible - in this case, check with a multimeter in the “continuity” mode.

4. Install a new fuse.

   It must be the same denomination! Make sure the contacts are clean and the fuse is firmly seated in the socket.

If after replacement the fuse blows again, the problem lies deeper in the circuit. In this case:

• 🔧 Check the wires for chafing or short circuits (especially in bends, such as near doors).
• 🔋 Measure the voltage in the circuit with a multimeter - it should not exceed 12.6 V (with the engine off).
• 🚨 If you are not confident in your abilities, contact an auto electrician - incorrect repairs can lead to the failure of expensive units.

What to do if the fuse is stuck to the contacts?

If the fuse cannot be removed from the socket, do not use excessive force - you may damage the unit board. Instead:

1. Spray contacts WD-40 or Liqui Moly Kontakt-Spray.

2. Gently rock the fuse from side to side with tweezers.

3. If that doesn’t help, heat the contacts with a hairdryer (do not overheat the plastic!).

4. As a last resort, use a thin screwdriver, prying the fuse on both sides.

Relay in Nissan Sunny FB15: how to check and replace

Relay in Sunny FB15 are responsible for turning on powerful consumers: starter, fans, fuel pump. Their malfunction manifests itself in different ways: from headlight failure to the inability to start the engine. Unlike fuses, relays can be tested without replacement.

To diagnose the relay, you will need a multimeter or a simple 12 V light bulb. Test algorithm:

1. Remove the relay from the block.

   Pay attention to the markings (for example, K3 for a fan). The relay body is usually marked with a contact diagram.

2. Check the winding.

   Connect the multimeter in resistance measurement mode to the contacts 85 And 86. The resistance should be between 50–120 Ohms. If the device shows a break, the relay is faulty.

3. Check your contacts.

   Connect 12V to pins 85 And 86 - a click should be heard (contacts closing 30 And 87). If there is no click, the relay needs to be replaced.

If the relay is OK, but the device (for example, a fan) does not work, the problem may be:

• 🔌 fuse — check the corresponding element in the block.
• 🔌 Wiring - Inspect the connectors for oxidation.
• 🔌 Sensor - for example, the temperature sensor may not send a signal to turn on the fan.

B Sunny FB15 relays are interchangeable if they have the same contact markings. For example, fan relay (K3) you can temporarily replace the horn relay (K6), if they are of the same type.

⚠️ Attention: Some relays (eg K8 for generator) have a specific design. Replacing them with ones of similar size, but with a different internal device, can lead to failure of the generator or ECU.

Frequently asked questions about fuses and relays Nissan Sunny FB15

Why does it blow again after replacing the cigarette lighter fuse?

This indicates a short circuit in the circuit. Most often the problem is:

• A faulty device connected to the cigarette lighter (for example, a non-standard charger).
• Damaged wiring behind the dashboard (frayed wires or melted insulation).
• Oxidized contacts of the cigarette lighter connector.

Solution: turn off all devices, check the circuit with a multimeter in “test” mode. If there is no short circuit, connect gadgets one at a time to identify the culprit.

How can you tell if the starter relay is faulty and not the starter itself?

If you hear clicks when you turn the ignition key, but the starter does not turn, the problem may be:

1. Starter relay (K1 in the engine compartment) - check it as described above.
2. Contacts on the starter - inspect the terminals, clean from oxidation.
3. Battery - voltage must be at least 12.4 V.

To accurately diagnose a relay, swap it with a known good one (for example, a fan relay). If the starter starts working, the relay is faulty.

Can fuses of a different rating be used?

Absolutely not! Installing a fuse with a higher rating (for example, 20 A instead of 10 A) can lead to:

• Overheating and melting of wiring.
• Fire in the fuse box.
• Failure of expensive units (ECU, audio systems, etc.).

If a standard fuse blows too often, look for the cause (short circuit, faulty device) rather than increase the rating.

Where to buy fuses and relays for Sunny FB15?

Standard fuses and relays can be purchased:

• 🛒 At official dealerships Nissan (original art. 28510-JK00A for the fuse box).
• 🛒 In auto stores (analogues from Bosch, Hella or Valeo).
• 🛒 On AliExpress or eBay (check compatibility by VIN code).

The cost of fuses is from 50 rubles per piece, relays are from 300 rubles. For Sunny FB15 standard type fuses are suitable ATO/ATC (knife).

How to reset ECU errors after replacing a fuse?

If the engine control unit fuse has blown (№20 in the cabin unit), after replacement, errors may remain in the memory ECU. To reset them:

1. Disconnect the negative terminal of the battery for 10-15 minutes (this will reset temporary errors).
2. If errors remain, use a diagnostic scanner (ELM327, Launch CReader etc.) and perform a reset through the program (Torque Pro, Nissan DataScan).
3. In difficult cases (for example, an error P0600 - malfunction ECU) contact a service station to reflash the unit.