Nissan Sunny FB15 (1990–1995) is a legendary Japanese sedan that is still in use in many countries. Like any car of considerable age, it requires special attention to electrics. Fuses are the “weak link” that first signals problems in the on-board network. But where to look for them? What rating is needed for headlights or heater? And what should you do if the fuse blows over and over again?
In this article you will find complete layout of fuses and relays for FB15, decoding of each element indicating the current strength, as well as step-by-step diagnostic instructions and replacement. We will analyze the typical mistakes of owners that lead to short circuits and give recommendations on choosing high-quality fuses. If your Sunny suddenly “goes deaf” or refuses to start - start checking with them.
Where are the fuse boxes located in Nissan Sunny FB15
B FB15 fuses and relays are distributed across three main blocks:
- 🔧 Main unit in the cabin — located to the left of the steering column, under the instrument panel. To gain access, you need to snap off the plastic cover (it is held on by two latches).
- 🔋 Block under the hood — located next to the battery, in a plastic box with a black lid. High current fuses are concentrated here (for example, for a radiator fan).
- 🚗 Additional relay block — in some modifications it is installed behind the glove compartment or under the center console. Responsible for climate control and audio system.
Important: on export versions Sunny (for example, for the US or European market) the location of the blocks may differ slightly. If you do not find a fuse according to the standard diagram, check service book or a label on the back of the unit cover.
- To the left of the steering wheel
- Under the hood
- Behind the glove compartment
- No additional block
- I don't know
Fuse diagram and decoding FB15 (cabin block)
The main cabin unit contains 20–25 fuses (depending on the configuration) and 5–7 relays. Below is a table with a breakdown for the most common version Sunny FB15 1.6i (GA16DE):
| Fuse no. | Denomination (A) | Purpose | Symptoms of a problem |
|---|---|---|---|
| 1 | 10 | Interior lighting, instrument lighting | The lamps in the shades do not light, the panel light is dim |
| 5 | 15 | Low beam (left headlight) | Low beam on one side does not work |
| 10 | 20 | Windshield wipers, windshield washer | The wipers do not move, no liquid splashes |
| 15 | 30 | Heater (stove), climate control fan | Warm air does not blow, fan does not turn on |
| 20 | 10 | Audio system, cigarette lighter | The radio does not turn on, the cigarette lighter does not work |
Attention: fuse No. 12 (10A) is responsible for the ECU (electronic engine control unit). Its burnout can lead to ignition failure or unstable engine operation. If this fuse burns out repeatedly, diagnostics of the wiring or the ECU itself is required.
How to check a fuse without a tester?
Visually inspect the metal thread inside the fuse - if it is broken or melted, the part must be replaced. You can also use the “replacement method”: install a known-good fuse of the same rating and check whether the circuit is functioning again.
Fuses under the hood: what you need to know
Block under the hood FB15 contains 5–8 high rated fuses (from 30 to 100A) and 2–3 relays. They protect circuits with high current consumption:
- ⚡ Main fuse (80–100A) - powers the entire on-board network. Its burnout is equivalent to “de-energizing” the car.
- 🔥 Radiator fan (30–40A) - if it burns out, the engine will overheat.
- 💡 Headlights (high beam) (20A) - separate fuse for right and left lights.
- 🔋 Generator (60A) - protects the battery charging circuit.
⚠️ Attention: Never replace fuses under the hood with bugs (jumper wires). This may lead to fire in the engine compartment, especially if the problem is in the generator or starter circuit. In emergency cases, use a fuse 1-2A less than the nominal value (for example, instead of 30A - 25A), but only for a temporary trip to a service station.
To get to the block, remove the cover (it is attached to two plastic clips) and clean the contacts from oxidation. If the fuse is stuck, do not pull it out with pliers, but gently rock it from side to side.
☑️ Diagnostics of fuses under the hood
Common Fuse Problems FB15 and their reasons
If the fuses are in your Sunny burn out regularly, this is a signal about serious malfunctions. Here are the most common reasons:
- Short circuit in wiring. Chains are especially vulnerable:
- 🔌 Windshield wipers (wires rub against the body in the windshield area).
- 💡 Lighting (rubbed insulation under the hood or in the doors).
- 🔥 Stoves (heating element wires often melt).
- Faulty consumers. For example:
- 🚗 Starter (if the fuse burns out when turning the key).
- 🔊 Audio system (short circuit in speakers or radio).
- 💨 Cooling fan (jammed motor).
🔍 How to find a problematic circuit? If a fuse blows immediately after replacement, turn off all consumers in that circuit one by one. For example, for fuse #10 (windshield wipers), check:
- The performance of the wiper motor.
- Integrity of wires from the block to the motor.
- The power button on the steering wheel switch is working properly.
If the fuse burns when the ignition is turned on, but all consumers are turned off, there is a problem in the wiring between the fuse box and the ignition switch. Check the wiring harness under the steering wheel.
How to properly replace a fuse: step-by-step instructions
Replacing the fuse in FB15 It seems like a simple operation, but even here there are nuances. Follow this algorithm to avoid errors:
- Turn off the ignition and remove the negative terminal from the battery (especially if you are working with the unit under the hood).
- Find the faulty fuse. Use the diagram from the previous section or the label on the unit cover.
- Remove the fuse special tongs (they are usually attached to the block cover). If there are no pliers, use tweezers, but do not pry the fuse with a screwdriver!
- Check the circuit. Before installing a new fuse, turn on the ignition and check if the contact is sparking (this is a sign of a short circuit).
- Install a new fuse the same denomination. No “bugs” or fuses “by eye”!
⚠️ Attention: If after replacement the fuse burns out again - do not repeat the operation. Each time a fuse blows, a micro-explosion occurs, which damages the contacts of the unit. It is better to immediately contact an auto electrician for diagnosis.
For FB15 Fits standard size fuses ATO/ATC (knife). Recommended brands:
- 🔹 Littlefuse - original fuses used on the Nissan assembly line.
- 🔹 Bussmann - reliable and affordable.
- 🔹 Hella — premium segment, resistant to vibrations.
Never use fuses with a rating higher than that specified in the diagram. For example, if the circuit should have 15A, but you put 20A, you risk burning the wiring or device (for example, an ECU).
Relay in Nissan Sunny FB15: location and diagnosis
Relay in FB15 are responsible for turning on powerful consumers: starter, headlights, cooling fan, etc. Their malfunction manifests itself differently than that of fuses: the circuit does not open, and the device simply does not turn on. For example:
- 🔦 The headlights do not shine, but the fuse is intact → check the low/high beam relay.
- 🚗 The starter does not turn, although the battery is charged → starter relay or solenoid relay.
- 💨 Radiator fan does not turn on when overheated → fan relay.
B FB15 relays are located:
- 🔧 In the main cabin unit (next to the fuses).
- 🚗 Under the hood (in the same block as the high current fuses).
- 🔌 Behind the glove compartment (in some trim levels).
🔧 How to check the relay?
- Remove the relay from the socket (by gently pulling up).
- Look at the markings (eg
12V 30A). - Use the multimeter in dialing mode:
- Contacts
85And86(coil) should ring with a resistance of ~50–120 Ohms. - Contacts
30And87(power section) are open in the normal state, but when 12V is supplied to the coil, they are closed.
- Contacts
If the relay is faulty, replace it with a new one with the same marking. For FB15 Fits standard size relays ISO 280 (For example, Omron G2R or Tyco V23134).
Frequently asked questions about fuses Nissan Sunny FB15
Why does the cigarette lighter fuse burn out when connecting the navigator?
Most likely, the problem is in the navigator itself or its power cord. Cheap devices often have a short circuit in the connector USB or power supply. Try connecting the navigator via another adapter (for example, from a smartphone). If the fuse burns out again, check the cigarette lighter circuit for a short circuit with the body (often the wires rub against the metal under the dashboard).
Can fuses from other Nissans (for example, Almera N16) be used?
Yes, but with reservations. Fuses ATO/ATC are universal, so they will fit any Nissan model (or even other brands). However, the denomination must strictly comply scheme FB15. For example, the heater fuse in Almera N16 maybe 25A, but Sunny FB15 - at 30A. Also pay attention to the color: Nissan uses standard color coding (for example, 10A - red, 15A - blue).
What to do if the main fuse under the hood (100A) has blown?
A blown main fuse is a serious signal. The reasons may be as follows:
- Short circuit in the generator circuit (check the diode bridge).
- Short circuit in the starter or power cable from the battery.
- Malfunction in the ECU power supply circuit (for example, after unsuccessful “lighting”).
⚠️ Do not replace it yourself! Without diagnostics, you risk burning the wiring or the ECU. Have your car towed to a service station or call an auto electrician.
How to protect fuses from oxidation?
Contact oxidation is a common problem in older cars. To prevent this:
- 🧴 Clean the fuse box contacts 1–2 times a year special spray (for example, CRC Contact Cleaner).
- 🔌 Apply a thin layer to the contacts dielectric grease (For example, Liqui Moly Electronic-Spray).
- 💧 Avoid getting moisture into the unit (check the lid seals).
If the contacts have already oxidized, clean them with fine sandpaper (P1200) or an eraser, then spray.
Where to buy original fuses for FB15?
Genuine Nissan fuses have a part number 24540-31U00 (set of 10 pieces of different denominations). You can buy them:
- 🛒 At official Nissan dealerships (but they often order them to order).
- 🌍 On AliExpress or eBay (search by article).
- 🏬 In auto parts stores (for example, Autodoc, Exist), where analogues from Littlefuse or Bussmann.
The cost of the original set is approx. 300–500 rubles. Analogues will cost less (100–200 rubles per set).