Nissan Sunny starter relay: diagnostics, replacement and selection of spare parts

Starter relay in Nissan Sunny (especially in models B13, B14 and B15) is a small but critical element of the engine starting system. Its failure can lead to complete failure of the starter, even if the electric motor itself and the battery are working properly. Unlike the retractor relay, which is located directly on the starter, main starter relay usually located in the mounting block under the hood or in the passenger compartment - and its diagnosis requires knowledge of the connection diagram and the ability to work with a multimeter.

In this article we will look at unique symptoms of a starter relay malfunction specifically for Sunny (including rare symptoms that are often confused with a breakdown of the ignition switch or immobilizer), we will show how to check the element without dismantling, and provide a compatibility table with analogues from other manufacturers. We will pay special attention to models with engines GA14DE, GA16DE and SR20DE, where the relay connection diagrams are different.

Where is the starter relay located in Nissan Sunny

The location of the relay depends on the year of manufacture and equipment of the car. In most cases it can be found in one of two places:

• 🔧 Mounting block in the cabin (under the instrument panel, next to the fuse box). Relevant for Sunny B13 (1990–1995) and early B14 (1995–1998). The relay is usually marked as STARTER RELAY or has a number 25730-4M000.
• 🚗 Relay box under the hood (near the battery or on the left mudguard). Characteristic for Sunny B15 (1998–2004) and models with SR20DE. Here the relay can be combined with the starter fuse in one unit.

On some export versions (for example, for the Japanese market), the starter relay is integrated into main body control module (BCM). In this case, replacement requires flashing or using the original unit. To accurately identify the location, check your modification's wiring diagram - it is attached to the inside of the fuse box cover.

If you do not find the relay in standard places, pay attention to additional relay block behind the glove compartment - it was installed on cars with air conditioning or automatic transmission. In such cases, the starter relay may be labeled as IGNITION CUT RELAY.

Signs of a bad starter relay

Symptoms of a broken starter relay on Nissan Sunny often disguised as other faults. Here are the key signs that point specifically to the relay:

• 🔊 Starter clicking without cranking. When you turn the key, you hear a distinct click (the retractor is activated), but the starter does not rotate. This suggests that the relay does not transmit current to the winding.
• 🔄 The starter works every once in a while. For example, the car won’t start the first time, but it starts the second time. A typical sign of burnt contacts inside the relay.
• 🔥 Smells like burning from under the hood. During prolonged attempts to start, the relay may overheat, which leads to melting of the housing or contacts.
• 🚨 The immobilizer light comes on. On Sunny B14/B15 A faulty starter relay can cause the immobilizer to trigger falsely because it is connected to the ignition circuit.

It is important to distinguish a relay failure from a malfunction solenoid relay (which is located on the starter) or ignition switch contact group. To do this, just check the availability +12V on the relay control wire when the key is turned. If there is voltage, but the starter does not work, the relay or the wiring after it is to blame.

How to test the starter relay with a multimeter

Diagnostics of the starter relay does not require dismantling the unit - just a multimeter and a screwdriver are enough. Follow the step by step instructions:

1. Remove the fuse box cover and locate the starter relay (see section above).
2. Check the voltage at the contacts:
   • 🔋 Contact 85 (manager) must show 0V with the ignition off and ~12V when turning the key to position START.
   • 🔌 Contact 86 (ground) must be permanently connected to the body.
   • ⚡ Contact 30 (power) must have 12V permanently (direct connection to the battery).
   • 🔌 Contact 87 (starter output) should show 12V only when the relay is activated.

Ring the relay coil: resistance between 85 And 86 must be within 50–120 Ohm.

Check the power circuit: between 30 And 87 there must be resistance 0 ohm (when submitting 12V on 85).

If at least one of the tests fails, the relay is faulty. Also note melted contacts or signs of corrosion on the legs. In 80% of cases, the problem is solved by replacing the relay, but if the contacts in the fuse block are burnt, they need to be cleaned or the entire block replaced.

Starter relay compatibility table for Nissan Sunny

Original starter relay for Nissan Sunny has an article number 25730-4M000 (or 25730-4M001 for models with automatic transmission). However, it can be replaced with analogues from other manufacturers. Below is a compatibility table with proven substitutes:

Manufacturer	Article	Applicability	Notes
Nissan (OEM)	25730-4M000	Sunny B13/B14/B15	Original, best quality
Bosch	0 332 014 150	All models	High resource, but more expensive
Hella	4RA 003 507-331	B13, B14	Suitable for low power starters
Meat & Doria	88.3770	B15 (SR20DE)	Budget option, possible burning
Panasonic	AZ257304M000	All models	Japanese quality, full analogue of OEM

When choosing an analogue, pay attention to switching current - for Sunny it must be no less 30A. Relays with lower current (for example, 20A) will quickly fail due to the high load of the starter. Also check contact type: on some Chinese relays, the legs are thinner than the original ones, which leads to poor contact in the block.

Step-by-step replacement of the starter relay

Replacing the starter relay with Nissan Sunny takes no more than 10 minutes, but requires care. You will need:

• 🔧 Flat screwdriver (for removing the block cover).
• 🔌 Tweezers or small pliers (for removing the relay).
• 🧴 Contact lubricant (for example, Liqui Moly Kontakt-Spray).

Instructions:

1. Disable negative battery terminal (required!).
2. Remove the fuse box cover (on B15 it is attached with latches, on B13/B14 - on screws).
3. Locate the starter relay and carefully remove it with tweezers. Don't pull the wires!
4. Clean the contacts in the block from oxidation (you can use an eraser or fine sandpaper).
5. Install the new relay, having first applied it to the legs contact lubricant.
6. Check starter operation before assembly: Connect the battery and try to start the car.

If the starter does not work after replacement, check:

• 🔋 Availability 12V on contact 85 when turning the key.
• 🔌 Integrity of the starter fuse (usually 10A, located next to the relay).
• 🔧 Condition of the ignition switch contact group (a common problem on Sunny B14).

What to do if the new relay does not work?

Check the circuit from the ignition switch to the relay - the wire in the corrugation under the steering wheel often frays. Also inspect the solenoid relay on the starter: if it is “stuck,” it blocks the operation of the main relay.

Frequent mistakes during diagnostics and repairs

Even experienced car owners make mistakes when working with the starter relay. Here are the most common:

⚠️ Attention: Never test the starter relay “for spark” by shorting the contacts with a screwdriver! This may burn out the starter winding or engine control unit (ECU).

• ❌ Ignoring the fuse. On Sunny B15 starter fuse (10A) often burns out when there is a short circuit in the relay circuit. Replacing it solves the problem in 30% of cases.
• ❌ Confusion with the retractor relay. Many people change the main relay, although the problem is retractor (located on the starter). To distinguish: if, when you close the contacts on the retractor with a screwdriver, the starter turns, it is the fault, and not the main relay.
• ❌ Incorrect relay installation. On some relays the contacts 30 And 87 are located mirrored. If you mix it up, the starter will work in the opposite direction (relevant for Sunny with automatic transmission).

Another common mistake is relay test without load. For example, if you ring the winding without connecting to the on-board network, you may not notice burnt contacts that only appear under current. Always test the relay under a real load (for example, by connecting a light bulb 21W between 30 And 87).

Prevention and increase in relay life

Starter relay in Nissan Sunny serves on average 100–150 thousand km, but this period can be extended by following simple rules:

• 🔋 Monitor the battery charge. A discharged battery causes the starter to operate longer, which increases the load on the relay.
• 🔌 Clean your contacts fuse box once a year. Oxidation impairs conductivity and causes the relay to overheat.
• 🚗 Do not hold the key in position START longer than 5 seconds. If the car doesn't start, pause 30 secondsso that the relay cools down.
• 🔧 Use quality spare parts. Cheap relays without a heatsink overheat and fail within 20–30 thousand km.

On vehicles with gas cylinder equipment (GBO) The starter relay wears out faster due to the increased load when starting on gas. In this case, it is recommended to install additional relay (For example, Bosch 0 332 209 150), which will reduce the current through the standard relay.

💡

If you frequently drive off-road or in high humidity conditions, treat the fuse box silicone grease - this will prevent corrosion of the contacts.

FAQ: Frequently asked questions about the Nissan Sunny starter relay

Is it possible to drive with a faulty starter relay?

Technically it is possible, but it is inconvenient: the car will have to be started “from the pusher” or by closing the starter contacts directly. However Driving for a long time with a faulty relay is dangerous: The starter winding may burn out or the engine control unit (ECU) may be damaged due to voltage surges.

Why does the starter spin after replacing the relay, but the car does not start?

Probable reasons:

• Faulty solenoid relay (does not retract the bendix).
• Problems with immobilizer (on B14/B15 it blocks starting if the starter relay is faulty).
• Open circuit between relay and starter (check wire red/black).

Which starter relay is suitable for Nissan Sunny with diesel engine?

For diesel Sunny (for example, with CD20) you need a relay with increased switching current - no less 40A. Suitable:

• Nissan 25730-4M010 (original).
• Bosch 0 332 209 150 (universal).

Conventional relays 30A quickly fail due to the high starting current of the diesel engine.

How to distinguish a relay failure from a starter failure?

Simple test:

1. Turn the key to position START and listen: if you can hear click (the retractor works), but the starter does not turn - it’s to blame relay or power circuit.
2. If there is no click, the problem is solenoid relay, ignition switch or immobilizer.

You can also close the contacts with a screwdriver 30 And 87 on the relay - if the starter starts working, the relay is faulty.

Where to buy an original starter relay for Nissan Sunny?

Original relay 25730-4M000 can be found:

• At official dealerships Nissan (price ~1500–2000 rub.).
• On AliExpress or eBay (search by article, price ~500–800 rubles, but there is a risk of running into a fake).
• In Japanese spare parts stores (for example, Amayama, BuyJapanParts).

Before purchasing, check that the relay body is marked NISSAN And 12V 30A.