One of the problems with the car engine starting system is when the starter does not stop after the driver has released the ignition key. Regardless of the cause, this problem can result in a mechanical failure of the assembly, as it is not designed for long-term operation. Therefore, the first step is to forcibly stop the starter, and only then think about what happened. From this material you will learn: what to do if the starter turns after starting the engine; how it works and turns off in good condition; 7 possible causes of failure and their elimination.
The starter turns and does not stop - what to do?
If the starter continues to spin after starting the engine, you need to act as quickly and decisively as possible. No panic. Cool and confident. The faster you do the right thing, the greater the chance that the starter will not completely collapse.
To stop the starter, which did not turn off by itself, it must be de-energized. To do this, remove any one terminal from the battery. If you don’t have the right key at hand, disconnect the wire with any means at hand (knife, wire cutters, tear off with your hand). In this situation, a damaged wire or terminal will cost much less than replacing a destroyed starter.
Any car engine is equipped with an electric starter and a generator. If we draw an analogy with sports, then the generator is a marathon runner. It is structurally designed for long-term operation. A starter is an athlete who lifts a heavy barbell. His task is to work at the maximum capacity for a few seconds.
The starter is not designed for long-term operation. In this mode, it either burns out or breaks mechanically. That is why it is important to stop the starter as soon as possible if it does not turn off by itself. Of course, it can withstand constant rotation for several minutes. But its resources after such an operation will be greatly reduced.
Algorithm for the operation of an automobile electric starter
Diagnostics and repair of any device is greatly simplified if there is an understanding of how it works. On this site, this approach is in any material. Many readers, after getting acquainted with the device and the principle of operation of a particular automotive unit, guess what the problem might be. And those who did not guess themselves find understandable options further down the text.
The car engine start system consists of the following key elements:
- Accumulator battery.
- Electric starter.
- Retractor relay.
- Ignition lock.
- Power and signal wires.
The battery provides power to the starter. This is her main task. Whereas the power supply of other consumers with the engine off is all secondary functions. First of all, the battery is needed for the starter. That is why starter batteries are installed on machines, and not traction batteries.
The starter is a simple commutator motor. It works when power is supplied to it. Minus power is supplied to the starter through the "mass". Plus, it is connected with a thick wire from the battery through the contacts of the solenoid relay.
The solenoid relay is a device that controls the electrical and mechanical operation of the starter. When it is triggered, plus power is supplied to the starter through the power contacts from the battery. This happens due to the fact that the armature of the solenoid relay moves inward, pressing on the rod with the contact plate until it comes into contact with the power leads. One of them is constantly connected to a plus with a battery. The second is connected to the brushes and starter windings. When the plate closes the contacts, the plus from the battery goes to the starter and it starts to rotate (there is always a minus on it).
The second function of the retractor relay is to move the bendix towards the flywheel crown.
When the driver releases the ignition key, the solenoid relay de-energizes, stopping the starter.
Ignition lock - one of its functions is to turn on and off the power to the windings of the solenoid relay.
Launch system operation algorithm:
- The driver turns the ignition key to the "start" position.
- The pull-in winding of the solenoid is energized and triggered, generating a magnetic field.
- Under the influence of a magnetic field, the armature of the solenoid relay moves inward.
- At this moment, three events occur at once - the holding winding is activated, power is supplied to the starter, the bendix is connected to the flywheel.
- The engine starts.
- After starting, the starter continues to rotate until the driver releases the ignition key. The overrunning clutch protects it from damage.
- The driver releases the ignition key - the holding winding is de-energized, the armature of the solenoid relay returns to its original position, the starter power is cut off, the bendix is disengaged from the flywheel.
This is how a good car starter works. Surely many of you already have ideas why the starter may not turn off after starting the engine.
The starter does not turn off: possible causes and their elimination
The following are 7 possible problems due to which the starter does not stop. In 90% of cases, this is due to the first reason considered. The rest of the options are quite rare in practice. But you should also be aware of them.
Cause 1. The contact plate is stuck to the power contacts
The same contact plate inside the solenoid relay, which moves to the power contacts and passes current through itself to power the starter. In good condition, it moves back to its original position under the influence of a spring.
The sticking of the contact plate occurs due to the fact that a large current passes through it. As it oxidizes, the electrical contact gradually deteriorates. As a result, only a small area of contact remains, through which the entire starting current passes. This leads to partial melting of the materials and to welding.
If the solenoid relay can be disassembled, then the problem is easily fixed by cleaning or replacing the contact plate. Most solenoid relays have a non-separable design. In such cases, it is necessary to replace it completely.
How to make sure that the problem is in the contact plate, which is stuck to the bolts? You can check this using a conventional multimeter, included in the continuity mode. The probes of the device must be applied to the power terminals. If the circuit is closed, then the plate is stuck. In good condition, there should be no electrical contact between the power bolts of the solenoid relay.
Reason 2. The contacts in the ignition switch do not open
In this case, the holding coil of the solenoid relay continues to be energized after the driver releases the ignition key. The solenoid armature keeps the bendix engaged with the flywheel, while the starter continues to receive power from the battery. As a result, the starter turns along with the engine.
To fix this problem, you need to repair or replace the ignition switch.
How to make sure that it is the ignition switch that is to blame? To do this, you need a multimeter in DC voltage measurement mode in the range up to 20 volts. Before checking, disconnect all wires from the starter. Locate the signal wire coming from the ignition switch. Usually this is a thin wire that you disconnected from the solenoid relay. Connect battery. Connect the black probe to the "mass" of the car, and the red probe to this signal wire. If the device shows voltage, then the contacts in the ignition switch are constantly closed. They must be open if no one is holding the key in the "start" position.
Reason 3. Stuck armature of the retractor relay
The armature of the solenoid, after deactivation of the holding winding, returns to its original position under the influence of a spring. Due to this, the starter motor is de-energized and disengaged from the Bendix flywheel.
The solenoid armature may not return to its original position for two reasons. Firstly, the spring that pushes the anchor may be broken. Secondly, the spring force may not be enough to move the anchor. This can be interfered with by dirt or rust on fine-fitting surfaces.
You can verify this breakdown after dismantling the starter and retractor relay. The anchor should move easily in its clip, by hand. If it wedges, gets stuck, or it is impossible to pull it out of the retractor at all, this is the reason.
If the problem is slight contamination or corrosion, cleaning and lubricating the parts can be attempted. To lubricate the solenoid armature, you cannot use thick lubricants like lithol or grease. Perfect for these purposes is the usual motor or silicone (ideal) oil.
If, after cleaning and lubrication, the armature still moves in the cage with great difficulty, the solenoid relay must be replaced with a new one.
Reason 4. Jammed bendix
The overrunning clutch moves freely along the starter shaft in a worm gear. The bendix is easily returned to its original position by the armature of the solenoid, which is displaced by a spring. This can be prevented by dirt or rust on the starter shaft or the freewheel itself. To check this version, disassemble the starter and move the bendix along the shaft. This should work without any effort.
If the bendix moves with great difficulty or does not move at all, the cause must be eliminated. Most often, the usual cleaning and lubrication of the contacting parts helps. Sometimes the cause of the bendix jamming is a damaged worm gear. Remove the freewheel and inspect the helical teeth on it and on the starter shaft. If defects are found, replace the parts with new ones.
Reason 5. The bolts securing the starter to the engine have loosened
In this case, the position of the starter is skewed. The bendix is pressed against the flywheel crown, and the spring force is not enough to return it to its original position. This version is easy to verify. The starter is attached to the engine with two or three bolts. Try to reach out with the key. If it turns out that they are weakened, then the problem was precisely in this.
Reason 6. Worn starter bushings
Since the starter operates for a short time, it rarely uses ball or roller bearings. Usually the armature and the gear shaft rotate on two or three bronze bushings. When they wear out or break, the rotating parts warp. Most often, this leads to the fact that the starter turns badly, sluggishly, tightly. However, it also happens that due to skew, the bendix does not return to its original position. This is the reason why the starter does not turn off after starting the engine.
To identify worn or destroyed bushings, you must completely disassemble the starter. Check the play and inspect the bushings visually. If there is significant play or visible defects, replace the parts with new ones. There are different opinions about the lubrication of plain bearings. The author of this material, based on personal experience, is a supporter of the fact that the bushings do not need to be lubricated at all. If you really want, you can use silicone grease.
Cause 7. Other malfunctions inside the solenoid
In order for the starter to turn off in a timely manner, the solenoid relay must perform all its functions without fail. After it is de-energized, two or three springs are responsible for returning the parts to their original position (depending on the design).
The performance of the solenoid may occur due to the following faults:
- one of the springs has weakened;
- some spring broke;
- large wear of the armature surface, due to which it moves in a cage with a warp;
- wedges the rod, which moves the power contact plate.
In most cases, these problems are solved only by replacing the entire solenoid. If the device is collapsible, then you can try to replace worn or broken parts.
Why does the starter not turn off after starting the engine |
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Cause |
Diagnostics |
Repair |
Contact plate stuck |
Remove the starter from the engine, turn on the multimeter in continuity mode, check the circuit between the power contacts of the solenoid - if the circuit is closed, then the plate is stuck |
If the solenoid is collapsible, disassemble and clean the plate from carbon deposits and oxides, replace the non-collapsible part with a new one |
The contacts in the ignition switch do not open |
Disconnect the wires from the starter, connect the battery to the car's on-board network, check for voltage on the signal wire - if there is voltage, then the problem is in the ignition switch |
Repair sticking in the ignition switch or replace it with a new one |
Solenoid armature stuck |
Remove the starter from the car and disconnect the retractor, check how easily the anchor moves in its holder |
Remove dirt and rust or replace the solenoid with a new one |
Jammed bendix |
Remove the starter from the car and disassemble it, check how easily the overrunning clutch moves on the shaft |
If the bendix moves with great difficulty or is jammed at all, establish and eliminate the cause |
Loose bolts securing starter to engine |
Check if the bolts holding the starter to the engine are loose. |
Tighten the bolts |
Worn starter bushings |
Remove the starter from the engine and completely disassemble it, check the play and inspect the bushings for wear or damage |
Replace worn or damaged bushings with new ones. |
Other Solenoid Malfunctions |
Remove the retractor and press the anchor several times - you should feel the work of the springs both when pressed and when returning to its original position |
If the solenoid is collapsible, replace worn and broken parts, replace the non-collapsible assembly with a new one |
Other car electric starter malfunctions
The car engine start system is quite reliable and can work flawlessly for years. However, there are problems, of course. What, and how to deal with them, you can find out from the detailed materials on the Auto without Service Station website:
10 reasons why the starter turns bad
How to test the starter solenoid
Starter takes over: symptoms and underlying causes
The starter clicks but does not turn: symptoms and main causes
I recommend you take a look.