⚡👎 The starter turns off ahead of time: possible causes and repair

The malfunction considered in this material - when the starter turns briskly and stops abruptly ahead of time - is quite rare. More often it spins tight or clicks and doesn't spin. Although rare, this problem has at least 7 possible causes. What are these malfunctions, how to diagnose and repair them - you will learn from this article.

How does a good electric starter work?

But first, it’s worth briefly talking about what processes take place in the starter when it is in good condition and starts the engine. Usually, a clear understanding of the principle of operation helps to guess without prompting what kind of breakdowns could lead to the fact that the starter turns for a second or two, and turns off without starting the engine.

We will consider the principle of operation of the starter according to the following image.

The algorithm of the electric starter of the internal combustion engine:

1. The driver turns the ignition key to the "start" position.
2. Power is supplied to the retractor relay through the signal wire coming from the ignition switch.
3. The retracting winding 14 of the solenoid is turned on, creating a strong magnetic field.
4. The magnetic field acts on the armature 12 of the solenoid, and it moves to the right (in this diagram).
5. Moving, the anchor 12 pulls the lever 10, which pushes the bendix 5 towards the flywheel ring (gear 4 engages with it).
6. At the same time, the armature 12 presses the rod 16, closing the contacts 20 with the plate 18.
7. Connected to the upper contact 20, the plus from the battery passes through the plate 18, the lower contact 20 and the wire 21 to the brushes 22.
8. Starter armature 31 begins to rotate and start the engine.
9. At the same time, the retracting winding 14 is turned off, and the holding winding 13 is switched on instead. It is she who is responsible for ensuring that the starter rotates and does not turn off until the driver releases the ignition key.
10. When the engine starts, the starter continues to operate.
11. Since the speed of the crankshaft of a running engine is much higher than the speed of rotation of the starter shaft 1, the overrunning clutch 38 is activated. The starter remains engaged with the engine flywheel, but they rotate independently of each other.
12. The driver releases the ignition key.
13. The holding winding 13 is powered off, the magnetic field disappears and the armature 12 returns to its original position due to the force of the spring.
14. Bendix 5 returns to its original position and gear 4 is disengaged from the flywheel.
15. Plate 18 returns to its original position and power is no longer supplied to the starter motor - it stops.

This is how a good starter works. If there are certain malfunctions, the following symptoms may appear:

• the starter makes clicking sounds and does not rotate;
• the starter rotates tightly, sluggishly, reluctantly;
• the starter does not spin — vigorously rotates for a couple of seconds and stops abruptly.

This article is devoted to the analysis of the last symptom. Other problems are discussed in detail in the materials that you can find on the links on the Auto without a service station website.

The starter turns off ahead of time: possible malfunctions and repairs

The author of this article in practice met 7 possible reasons due to which the starter itself turns off without starting the engine. There may be other faults as well. If you know about them, please share in the comments below.

Fault 1. Interturn circuit of the holding winding of the solenoid

The holding winding is designed to maintain the operating mode of the starter. It is noticeably weaker than the retracting winding, since it does not need to overcome the forces of several springs. The task of the holding winding is to continue to create a magnetic field sufficient to hold the armature of the solenoid.

If the holding winding creates a too weak or unstable magnetic field, the solenoid armature under the influence of the springs spontaneously returns to its original position. Accordingly, the starter is switched off too early.

One of the most common reasons why the holding winding is not able to hold the solenoid armature to the end is an inter-turn short circuit. As a result of this malfunction, the winding creates a weak magnetic field, and after a second or two of operation, it overheats sharply and "releases" the armature altogether.

Although most solenoid relays are of a non-separable design, the holding coil can be easily checked. This procedure is detailed in the solenoid relay test article on this site. See the link.

If the check shows that the holding winding is defective, the solenoid relay should be replaced.

Fault 2. Discharged or "does not hold" the load of the battery

A car electric starter is essentially an electric motor. Very powerful. Depending on the type and size of the engine, it can consume a current of the order of 100 ... 400 amperes. With an on-board network voltage of 12 volts, this means a power of 1.2 ... 4.8 kilowatts. In order for the starter to work confidently until the engine is successfully started, the battery must be able to deliver this power for several seconds.

If the battery is poorly charged or almost "to zero", it first gives the starter a large current. But after a second, it can decrease so much that it will not be enough for any starter work. So he stops.

The same thing happens if a worn-out battery is installed on the machine. If its real capacity is much lower than the nominal one, then it is not capable of delivering the declared starting current. In addition, a worn battery under such a load as a starter will instantly lose voltage. This means that the power allocated to the starter also sags. Therefore, after a second of operation, the electric motor stops and the car does not start.

To check this version, you need to observe the voltage drop at the battery terminals while the starter is running. To do this, you can use both the voltmeter of the on-board network, and a separate device - a voltmeter or multimeter. If, when starting the engine, the voltage at the battery terminals drops below 9 volts, then this is the reason for the sudden stop of the starter.

A discharged battery must be recharged. Worn - replace.

How to properly charge the battery:

• Ca/Ca;
• AGM;
• GEL.

I also recommend material on why the battery charge indicator does not turn green.

Malfunction 3. The terminals on the battery terminals are poorly clamped

When the engine is started, a large current flows through the terminals on the battery. If the contact in this place is unreliable, the power supply of the car's on-board network may suddenly disappear. Accordingly, not only the starter stops - the control lamps for the battery charge and oil pressure on the dashboard also go out.

The main reasons for poor contact at the battery terminals are that they are not clamped enough or damaged. Check the bolts and tighten if necessary. Inspect the terminals carefully. If they have cracks or other damage, replace them. Another well-known cause of unreliable contact of the terminals with the battery is the oxidation of the terminals. Read on the link what kind of problem it is, how to fix it and prevent it.

Fault 4. Unstable contact in the starter power supply circuit

The minus power supply to the starter is supplied, as a rule, through a common "mass". Check this wire. Usually it is fixed on the body or engine. The contacts may have oxidized or rusted. To fix the problem, clean or replace them. In some cases, you have to make an additional "ground" wire.

Plus power supply to the starter is supplied through a thick wire. It goes directly from the battery to the power contact on the solenoid relay. It is in this place that oxides and corrosion often form, disrupting normal electrical contact. The problem is eliminated by cleaning the contact surfaces. Along the way, pay attention to the wire itself. It must not be damaged.

Fault 5. Unstable control signal from the ignition switch

In this case, a bad connection can be either in the ignition switch, or in the place where the signal wire is attached to the starter. Rather, to the output on the retractor relay. First of all, remove the wire from the starter and clean the contact surfaces from corrosion. Do not rush to install it. First, connect a multimeter or voltmeter to this wire (one probe to the wire, the other to ground) and ask an assistant to turn the ignition key to the "start" position. A constant voltage should appear on the signal wire, equal to the voltage at the battery terminals.

If, while holding the ignition key in the "start" position, the voltage on the signal wire is unstable or periodically disappears altogether, the problem lies in the ignition switch. Repair it or replace it with a new one.

Fault 6. Mechanical engine failure

The car starter is a very powerful electric motor. However, even this power may not be enough to stably turn the engine crankshaft with serious mechanical failures. In other words, if the engine is wedged, the starter will stop prematurely. The reason may be not only mechanical. On thematic forums, there is a problem with untimely ignition. A too early spark causes the air-fuel mixture to ignite early, pushing the piston backwards. The starter cannot overcome this movement and stops.

To fix this problem, you need a thorough diagnosis of the engine and its systems.

Fault 7. Dirt and rust inside the starter

The accumulation of dirt and rust inside the starter will often cause it to turn hard but slowly. However, in the presence of other factors described above, it may suddenly stop, as it does not have enough power to overcome the influencing resistance.

To eliminate this malfunction, you need to remove the starter from the engine, disassemble it completely, thoroughly clean and lubricate the rubbing parts.

That's all. I hope the material helped you find and eliminate the cause of the starter turning off too early.