Starter solenoid relay for VAZ 2109: checking the condition, replacing and repairing it yourself

Element Role

All VAZ cars, including model 2109, have a standard engine starting system, which is based on an electric starter. Here's what you need to know about him.

A starter is a small electric motor that is connected to the flywheel of the motor via a coupling (Bendix) for a short period of time to start the rotation of the flywheel.
Despite its small dimensions, the starter passes through itself enormous currents.
If the starter circuit were closed directly in the ignition switch, then not a single component of the system would be able to withstand such current loads. As a result, they would burn out.
Therefore, for these purposes, the starter is connected remotely to the battery via a relay. Its contacts are designed for high currents.
The starter operates briefly and must be turned off after the engine starts. Otherwise, its active destruction will begin due to the influence of motor power.
Relyushka performs these tasks perfectly. Actually, it is precisely to ensure the functioning of the system and protection against current, timely shutdown of the starter, a retractor relay is included in the design.

Element diagram

Starter activation relay VAZ 2108, 2109, 21099

On a VAZ 2108, 2109, 21099 and similar cars, the starter is turned on not directly, but through a relay.

Purpose of the starter switch relay VAZ 2108, 2109, 21099

The starter switch relay is designed to reduce the load on the ignition switch contacts when starting the engine with the starter. Since the starter is the most powerful consumer of electrical energy in the electrical equipment of a car, if it was turned on directly, the ignition switch would burn out very quickly.

— Where is the starter activation relay installed for VAZ 2108, 2109, 21099

The starter switch relay for VAZ 2108, 2109, 21099 is installed on the engine compartment panel.

Where is the starter relay installed?

— Starter activation relay device

The starter activation relay consists of a coil (copper wire winding) with a magnetic core located inside.

— How does the starter relay work?

After turning the key in the ignition switch to the “Starter” (II) position, its contacts “30” and “50” close. Voltage is supplied to the starter activation relay (relay contact “85”). It is triggered (the contacts inside the relay are closed) and supplies voltage to terminal “50” of the starter traction (retractor) relay. The retractor is activated and the starter turns.

— Connection diagram for starter relay

Starter connection diagram 29.3708 for VAZ 2108, 2109, 21099 cars

— Faulty starter relay

The most common malfunction of the switching relay is when the starter stops turning on.

Oxidation of relay contacts or ground

"Open" in the relay windings

Relay burnout due to short circuit

A “break” in the electrical circuit may also occur, which should be taken into account when diagnosing a malfunction.

“Culprits” of the malfunction of the VAZ 21083 starter relay

A faulty relay must be replaced with a new one; if the contacts are oxidized, we clean them and check its operation.

— Applicability of the starter activation relay on VAZ 2108, 2109, 21099 vehicles

In the electrical circuit for switching on the starter of a VAZ 2108, 2109, 21099 car and their modifications, a starter switch relay 111.3747-10, 97.3747-10 and their analogs are used.

— Characteristics of the starter activation relay 111.3747-10

Rated voltage - 12 V

Operation voltage: no more than 8 V

Release voltage - 1.5 - 5.5 V

Load current - 20/30 A

Winding resistance - 85±5 Ohm

Notes and additions

The starter is the most powerful consumer of electrical energy in a car's electrical equipment (1.3 kW). When starting the engine, the current consumed by it can reach 400 A, which is a lot. Therefore, all connections in its electrical circuit must have reliable contact. Otherwise, the starter may “shoe” because its collector is dirty.

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Checking status

Before changing the relay, make sure that the problem with starting the engine is related to this component.

To do this, consider two situations that indicate its malfunction.

Situation	Your actions
The relay makes clicks, but the armature does not spin	If there are clicks from the relay, check the condition of the armature. To do this, the terminals of the retractor relay are bridged with a large screwdriver or a piece of welding cable to the terminals at the ends. Taking a thin wire or a screwdriver can easily burn the terminals. When the armature is working, after closing the terminals, the armature will spin, which can be determined by the sound. Consequently, the solenoid relay itself has failed and requires repair.
The relay is completely silent	Even if there is silence after closing the terminals, the problem should be looked for in the starter. The relay no longer plays any role here.

Having discovered that the relay has served its purpose, it must be replaced or repaired, if possible.

Causes and solutions to the problem

All faults can be divided into two categories:

the breakdown lies in the starter and retractor relay;
the starter armature rotates and the relay clicks;

The most common reason for a relay to not work is that the soldering point of the wire to the terminal has lost contact. Before disassembling the device, just try soldering these places with a soldering iron - the problem is solved. Well, if the starter still does not work, then the relay will have to be disassembled. Sometimes the coil that creates the electromagnetic field burns out. Simply replacing the old wire with a new one eliminates the problem; to do this, you just need to rewind the coil with your own hands.

Dismantling

There should be no problems with the dismantling process. The main thing here is to remove the starter, since the required relay is held on it. Therefore, dismantling is carried out as an assembly.

Turn on the handbrake, disconnect the battery by removing the negative terminal from it.
A wire with a large cross-section goes from the battery to the contact of the relay. It can be turned off by unscrewing it using a 13 key.
Remove the thin winding power wire from the solenoid relay.
Using the same 13mm wrench, unscrew the three mounting nuts holding the starter to the clutch block.
You can remove the device through the bottom or top. If you chose the top, then you need to slightly rotate the starter around its axis and remove it.
The lower output is more difficult, since here you need to remove the crankcase protection. But if parallel work is carried out that requires similar manipulations, problems will not arise.

Malfunctions of the VAZ 2109 starter retractor relay

Burnt contacts are the most common malfunction of the solenoid relay. A fairly large current passes through them (in the case of normal operation, approximately 80 A, if there is high rotation resistance - 300 A).

This leads to the formation of a spark gap, due to which the contacts burn and electrical conductivity decreases.

The second, common malfunction is associated with a break in the coil of the solenoid relay. If the winding breaks where it is soldered to the contact, this can be fixed. If the break occurs in the middle of the winding, you will have to completely change the solenoid relay.

On VAZ 2109 models, 2 types of starters are used:

with step-up gearbox;
with direct drive.

In starters with direct drive, torque is transmitted to the flywheel from the starter shaft; in starters with a gearbox, a step-up gearbox is located between the rotor and the starter flywheel.

You will find a large selection of refurbished starters for VAZ https://generstar.ru/prodaja/vosstanovlenie-startera/vaz/ in the GenerStar.ru workshop - request a call back and find out more details.

Before starting work related to the dismantling and installation of machine components, the vehicle must be set to the handbrake or speed. In addition, the negative terminal of the battery must be disconnected.

The battery is connected to the contact of the solenoid relay by a wire having a large cross-section. This wire must be disconnected by unscrewing the nut with a key 13.

Then you need to pull out the thin winding power wire from the solenoid relay. Using wrench 13 you need to unscrew the 3 nuts that secure the starter to the clutch block.

Compared to the classic VAZ 2109, this procedure is easier to perform. Thanks to the convenient location of all nuts.

To unscrew them, you do not need a socket wrench or cardan. The starter can be removed from the top (to do this you need to rotate it around its axis), or from the bottom (to do this you need to remove the crankcase protection).

After removing the starter from the car, you can begin to disassemble it. If this procedure has not been carried out for a long time, most likely, additional accessories will be required to repair it: a fork, brushes and bushings.

It must be remembered that VAZ 2109 starters are often not repairable or only partially repairable.

So, on the original VAZ 2109 starters, it’s easy to replace the brushes; you just need to unscrew the old ones from the contacts and screw in new ones instead.

Some manufacturers' brushes need to be welded or soldered. Soldering with tin is not particularly reliable due to the high current that can lead to melting.

Repair of the retractor relay VAZ 2109

To eliminate the main malfunctions of the solenoid relay (wire breakage and carbon deposits on the contacts), you will need to disassemble it.

First, unscrew the nut holding the wire that goes to the lower contact of the relay from the starter winding. After the relay is completely released, you can unscrew its housing from the starter using a screwdriver.

The VAZ 2109 starter solenoid relay includes a housing, winding, contacts, core and return spring.

The spring is responsible for disconnecting the rotor gear from the flywheel crown when the power to the relay winding is turned off.

The starter's rear cover is fixed to the housing. To gain access to the contacts, you need to unscrew the bolt and remove the cover. If there is carbon deposits on the contacts, it must be cleaned off using a needle file.

Now all that remains is to assemble the solenoid relay and check the resistance of its windings.

The resistance between the bottom-mounted solenoid relay bolt and the resistance contact should be approximately 0.5 Ohm. Between the body and the spade contact is approximately 0.7 ohms.

The VAZ 2109 starter solenoid relay has been repaired, good luck on the roads!

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Starter relay on VAZ 2109: fault diagnosis