DIY car alarm siren repair

During the operation of the car, it becomes necessary to repair its systems and assemblies. The security system in this regard is no exception. To save money, you can do it yourself. In this article, you will learn how to repair car alarms and key fob with your own hands.

All alarm faults can be conditionally divided into the following types:

• nutritional problems;
• wiring problems;
• software failure;
• false positives;
• malfunction in the key fob.

Let's take a closer look at each of the malfunctions in car alarms.

Power problems are often the cause of alarms not working properly. This can happen both with the equipment installed on the car and with the car alarm key fob. The system is de-energized due to a discharged vehicle battery. The car stops responding to the owner's commands. The battery, which serves as a power source for the key fob, can also be discharged. In this case, the lamp and display of the device will turn off. A decrease in the battery charge can be noticed in a timely manner by decreasing the range of the key fob.

Defects in the wiring sometimes become the cause of the system being de-energized. Over time, the contacts oxidize, which leads to the interruption of the transmission of electricity. The wires themselves may also be damaged. This happens during the installation of additional equipment or when attempting to steal the machine. Another reason is faulty fuses. The symptoms are the same as with power problems - the car does not respond to commands. This is provided that the key fob is in working order.

Sometimes car alarm malfunctions are caused by incorrect operation of the control unit - the "brain" of the system. This is due to a software failure.

These malfunctions are caused by errors in the setup or installation of the car alarm. If the sensitivity of the sensors is set too high, then the alarm will be triggered at the slightest shock or vibration. Alarms can be caused by small dry tree branches falling onto the machine, rain, or even a loud sound. Sensors set for optimal sensitivity, but installed on plastic parts, will also not work correctly. The fact is that plastic amplifies the vibrations that the sensors perceive. When heated, this material expands, which can trigger the sensors.

During operation, the key fob may start to work incorrectly or even break down. The reasons for this are wear and various damage caused by falling or exposure to water. A cracked display significantly reduces the information content and usability of the security complex. Dropping the key chain can also damage the quartz.

Before starting to repair car alarms, you need to find the cause of the malfunction. Completely different breakdowns can have the same symptoms. To accurately determine the cause of the malfunction, it is necessary to consider all possible options in stages.

You need to start with the key fob. Inspect it for mechanical damage and traces of water. If the key fob gets into water, condensation will form on the inside of the display lid. The operation of such a device (if it turns on) will be unstable. If the key fob did not fall and fell into the water, but the display is turned off and nothing happens when you press the buttons, then the discharged battery is to blame.

If the key fob is completely functional, but nothing happens when you press its buttons, then there may be two reasons for this - strong external interference or problems with the car and the alarm. Try to bring the key fob to the part of the car where the car alarm antenna is installed and press the button. If nothing happens, then the malfunctions need to be looked for in the car itself or in the alarm equipment installed on it.

Next, power and wiring diagnostics are performed. Check the battery charge and inspect the terminals for oxidation. The full charge of the battery can be easily determined by the operation of the on-board electronics. If everything is OK, then the next step is to check the wiring. To do this, you need a special tester with which the contacts are called. Inspect the wires for mechanical damage. Special attention should be paid to fuses. Usually they are in a box, which is located on the wire coming from the positive terminal of the battery.

If the cause has not yet been found, then a defect in the control unit or a failure of its software is to blame. It will not be possible to eliminate such a defect with your own hands, but with a software failure, everything is much easier - it is enough to carry out simple manipulations, which we will talk about below.

Most often, a car alarm key fob requires repair. The buttons wear out and begin to react poorly to pressing, and the device itself may fall on the asphalt or into a puddle. Button repair includes disassembling the case, cleaning the contacts and replacing the button pads (if necessary). To raise the recessed buttons, you can make a plastic backing that sticks to their seats on the board.

Most often, when the key fob falls from its board, quartz comes off. To eliminate this defect, it is enough to disassemble the keychain and solder the quartz to its original place.

To fix cracks in the display, you need to completely replace it. Remove the old display, strip the contacts and solder the cables of the new display. The process itself is not very complex and requires initial soldering skills. The difficulty lies in finding a new display. You can hardly find it in stores, so you will have to order from China via the Internet. Defects caused by water ingress cannot be eliminated by yourself.

Power and wiring problems are solved by stripping the battery contacts and terminals, and replacing fuses and damaged wires. To avoid unnecessary work, use the tester to find the exact cause of the problem and then fix it.

To eliminate the problem of false alarms, it is necessary to adjust the sensitivity of the sensors. The adjustment process is extremely simple. To do this, screw in or unscrew the adjusting screw located on the sensor housing.

To resolve software crashes, you need to reboot the system. To do this, de-energize it by disconnecting one of the terminals from the battery for a few minutes. If this does not help, then set the factory settings of the car alarm. Step-by-step instructions for resetting the settings can be found in the instructions for your alarm model.

The best way to test your car alarm is to use it as directed. Arming the car and try to open doors, trunk or hit the car. You should hit the wheels, hood and windows, gradually increasing the force of the impact. After checking the sensitivity setting of the sensors, open the car door with the key and try to start it, also using the key. The alarm should go off. Check the rest of the functionality, depending on the specific model, the functionality will be very different, we suggested how to check the basic and general alarm functions.

Most of the problems associated with the operation of car alarms can be eliminated by hand.It is better to entrust the repair of the control unit and other complex electronics to specialists. If, after following the above recommendations, the breakdown is not eliminated, then you need to contact a car service. To continue driving with a broken alarm, you need to master the process of turning it off with a secret button, which you can read about in the instructions for the car alarm.

In conferences, there are often questions about the types of sirens, their interchangeability and connection. This article has laid out some thoughts on the topic of simple sirens, in the hope that it will come in handy for someone when installing or replacing a siren.

It is very important: when connecting the mass of the siren, it is advisable to always use a welded standard bolt or nut on the body.

Simple sirens.

Simple or non-autonomous sirens are often called bells, they can be one-tone, many-tone, differ in power and shape of the body. But what they have in common is only two wires for connection. Most often, the black wire is connected to ground, and the red wire is connected to the alarm. It is better to check the exact connection according to the alarm installation diagram. There are alarms that control the siren by a minus signal (ground), for example Clifford Cyber ​​5. In such cases, the siren's positive wire is connected to the positive terminal of the battery using a fuse.

The big drawback of these sirens is that, having cut the wires, the siren becomes silent, as in the case if the battery terminal is removed or it is discharged.

But there are also advantages - these sirens can be compact and do not require maintenance, which means they can be hidden in inaccessible places. It is convenient to install such sirens as additional ones, to replace standard stand-alone sirens with them, or to install them secretly in the passenger compartment.

Of course, there is an exception, Medalion type Clifford sirens or the like, which is a speaker. But they are disabled in a similar way.

If your siren has a lot of tones, then the number of tones can be reduced to one or you can choose the ones you like. On some models, there is a window closed with an elastic band on the body of the siren, under it there are six jumpers - their removal of jumpers turns off the corresponding siren tone, later models have jumpers on the board in the form of wires or printed conductors, cutting of which leads to similar results.

Usually the consumption of such sirens does not exceed 2A.

Any simple sirens are interchangeable. They can also replace stand-alone sirens with the appropriate connection, depending on the control signal.

The defects encountered in these sirens are manifested in the form of a quiet sound or its complete absence.

The performance of the siren is checked by sending a signal (+) from the terminal of the standard battery to the red wire of the siren, in this case the second wire of the siren must be reliably connected to the vehicle ground. If the siren is controlled by a ground signal, then applying this signal to the black wire of the siren, while the second wire must be securely connected to the (+) battery terminal using a fuse.

Note that the siren ground wire is always black, and the signal control wire (+) can be of a different color, for example, white as in Scher-Khan alarms.

If the siren started working when a signal was given, then the malfunction consists either in a break in the control wire from the alarm, or in the failure of the control transistor. The integrity of the wire is checked by applying a control signal to the wire directly coming from the alarm connector. The health of the transistor is checked with a probe consisting of an LED and a resistor. With a positive control signal, a 1kOhm resistor is connected in series to the alarm output to the siren, the LED anode (in the form of a triangle shown in the diagrams) is connected to the resistor, the LED cathode is connected to ground (in the diagrams, it is represented by a dash).With negative control, the cathode of the LED is connected to the alarm output, the anode to the resistor, and the other terminal of the resistor to the positive terminal of the battery. If the output transistor is working and the panic signal is turned on, the LED should light up.

If the siren does not work with a direct control signal, then the cause of the malfunction lies in the siren itself. This can be a break in the speaker coil, failure of the transistors of the output stage of the siren or the tone shaping circuit. With a quiet siren signal, the output stage may partially burn out, or water may enter the siren's reflective deflector. The last reason is eliminated by drilling a small hole in the siren deflector.

It is very important: when connecting the mass of the siren, it is advisable to always use a welded standard bolt or nut on the body.

Standard stand-alone sirens.

We call them standard to distinguish them from the sirens of the Clifford, Cobra, Sikura and others. The difference between autonomous sirens and those described in the previous article, in the presence of a service key and a built-in battery, as well as four wires for control and power supply.

Disabling an autonomous siren with a key does not mean disabling the alarm and its interlocks, with the exception of specific sirens and monoblock alarms. The last two types are distinguished by the presence of more than four control and power wires.

There are always red and black wires, they are respectively connected to the battery positive and to the vehicle ground. With the mass it is clear, this was said at the very beginning. The plus is connected to the signaling supply wire and as close as possible to the connector. Let me explain why. The first - the siren will be protected by a fuse, the second - if the alarm harness going under the hood is cut, the autonomous siren will immediately turn on the signal due to loss of power (provided that it was turned on with a key).

There are still two wires left, which raise questions - where to connect them. Please note that when checking the siren, namely when connecting plus and mass, it does not scream, and regardless of whether the key is turned on or not. These two wires serve for the siren to scream. Usually they are signed with a “positive trigger” - a positive trigger and a “negative trigger” - a negative trigger. One of these wires is connected respectively to the signaling control wire. If in the “Panic” mode a signal (+) appears on the wire, then a positive trigger is used, and if the signal is ground (-), then a negative trigger is used. With such a connection of the siren, the main consumption goes through the power cable from the battery, and only low-current control from the alarm. And in this case, you can connect, if desired, an additional simple siren.

Some kind of autonomous sirens, of course with a reservation, can be cited as the fact that there are sirens, even with the key turned off, when a control signal is given, they can scream. Others must be included with a key.

The advantage of these sirens, as mentioned above, is that, having cut the wires, the siren continues to scream at the expense of its own battery. Of course, she screams a little more quietly, but this does not make it easier for the hijacker. And with a good internal battery, it can scream for quite a long time, although at night five minutes will be enough to perform its function. It is advisable to check the state of the internal battery of the siren from time to time by disconnecting the terminal of the standard battery or removing the alarm fuse when the siren is turned on with the key, so that this advantage does not turn into a disadvantage.

About the disadvantages. Since there is a key and a lock, it means that there must be access to the siren, and at the same time you cannot hide it far. The internal batteries of the siren can be destroyed while the siren turns into a simple one from an autonomous one, or worse, it starts to consume an increased current, thereby discharging the standard battery.

You can check the serviceability of the siren and the signaling output stage using the method described at the end of the article on simple sirens. The only difference is that the power on the red wire must be present, and the control signal is fed to the corresponding input to test the siren's performance. It remains to add only that a malfunction of the siren lock is possible, which sometimes crumbles or collapses, which makes it impossible to either turn on or off the siren.

Siren connection diagrams:

To test the sirens performance - the conductor with point “A” is the place where the control signal is sent. The verification method is described in the article about ordinary sirens. A prerequisite is the presence of power and ground on the siren wires.

A) Connection of a siren with positive alarm control. The dotted line shows a possible connection of an additional simple siren.

When replacing an autonomous siren with a simple one, according to the scheme at point “A”, the control from the autonomous siren is disconnected, and the simple siren becomes the main one. Insulate the power supply wire of the autonomous siren.

B) Connecting a siren with ground signal control. The dotted line shows a possible connection of an additional simple siren.

When replacing an autonomous siren with a simple one, according to the scheme at point “A”, the control from the autonomous siren is disconnected, and the simple siren becomes the main one. Insulate the power supply wire of the autonomous siren.

C) Connecting an autonomous siren with protection against disconnecting the alarm connector. The diagram shows two options.

The first one is using a standard connector. If there is an unused wire in the connector - for example, a positive trigger of doors or an output to an additional channel, then by cutting off the printed conductor, you can solder the hinged jumper inside the board. This contact will become the power wire of the autonomous siren and in case of power failure, the siren will turn on due to the built-in battery.

The second option is if a wire is soldered to the power contact inside the alarm and brought into the alarm harness, then the same result is obtained when the wire is broken or the connector is disconnected.

Likewise, you can protect the mass controlled siren.

D) Connection of several sirens.

Using this scheme, you can connect several additional simple sirens, hiding them, for example, in the cabin, trunk or in hard-to-reach places under the hood. Fuse 15 Ampere - is the main one for powering additional sirens, the relay decouples the current signaling output. Three-amp fuses for each of the add. sirens are needed if the hijacker finds a siren and closes the wires, the lower fuse rating of this siren will burn out, and the rest will remain working. In an emergency, the general fuse can be switched off.

Because the power of the autonomous siren is taken from the general power supply of the alarm, then in this case it can also be protected according to the scheme (B).

Good day to all.

To make it clearer what we are talking about - we are talking about a siren with a security alarm only instead of the standard "viu-viu" music plays whatever you want and download it.
I will not lay out the diagrams and information on the assembly. this information on Drive is enough to score in the search for "musical siren".
Well, if you think so, then in the times of generation it is no longer the “thumb” but the “index finger”, and when it is customary to choose what the soul likes - why not! After all, we select the ringtone on the phone or the beep melody, and if possible, then we will change the siren melody.
Personally, I was guided by an article - by the author - ZiperRZN
As it is now known, the "reader" of music from the SD card is the controller - Attiny85.
For some it is simple, for some it is difficult, but for some it is generally fantastic. But I am more than sure that after assembly this miracle did not always start to sing, this article is dedicated to the mistakes due to which it may not sing.

one.Firmware - you should pay special attention to Fuse-bits, or rather how to set them up in the firmware using the firmware manual. It's very simple - in the manuals 1 or 0 is indicated, in the firmware - 1 is a check mark, 0 is not a check mark. further in the picture I drew with arrows so that it was more clear to which bit which parameter.

Such a fuse bit as - RSTDISBL special attention to him, since it refers to the leg of MK “RESET” if there is no checkmark on it, it will be programmed to output and it will no longer be possible to reset and reflash the MK, the exit - to treat with - “Fuse bit the doctors". The Attiny 85's WAV reading firmware has a “Stereo” firmware, this leg is used to output the second channel. It is not needed for signaling! You are using “Mono” firmware!

2. SD card. I didn’t sing for me precisely because of the SD card, I tried it on old SD cards with 64MB and 128MB, it didn’t sing! have not changed to 4GB yet.
It must be formatted using the FAT32 file system.

3. The file itself. The format is known as WAV. I have flashed mine with firmware - “FULLSIRENA”,
She reads a Wav file with parameters:
Codec - "Microsoft Wave" "PCM"
Bit - 8
Mono
Frequency - up to 48,000Hz
Example on the prog - Sony Sound Forge

Power supply, or rather the stabilizer, MANDATORY - 3.3 volts, tk. more simply will disable the SD card!
The firmware that “FULLSIRENA” and that “sd8p_mo” are absolutely working!
I tried everything in expanded form on experimental boards.

Car alarms, like any other car system, can sometimes fail. If you are not an expert in the field of electronics, then it is better to entrust the repair of an alarm on a car in terms of its brains to a professional auto electrician.

There are situations when the alarm malfunction is not related to the operating system, and in this case it is quite possible to fix the breakdown with your own hands. In order not to panic ahead of time, not to transport your car to a car service, you need to have an idea of ​​the typical malfunctions of car alarms.

In this case, self-carried out repair of the car alarm will save you from unnecessary worries and unforeseen blows to the budget. To repair an alarm on a car, the traditional driver's tools should always be at hand: screwdrivers, wire cutters, electrical tape, a couple of wires, a tester (a light bulb with two wires for "ringing").

Important! If your car alarm is still under warranty, then, of course, you should not interfere with it yourself.

• Nutrition. The alarm does not respond to your clicks, or performs actions that you did not order. We start checking with the keychain, namely with the battery. Disassembling the keychain and replacing the battery will not take much time. A characteristic sign of a low battery is that the LED becomes dimmer, or the remote control range of the remote control decreases. Another reason for the failure of the remote control may be the ingress of water on it (when used in the rain).
• Wiring. No matter how complex or advanced car alarms, be it a conventional AOC buzzer (car security alarm) or a GSM alarm - under the influence of external factors, the contacts at the connection points are always oxidized. That is, car alarm repair always begins with ringing the contacts.
• The LED lights up brightly, and the alarm does not respond to pressing. In this case, we start repairing the alarm on a car by finding out the reasons for this phenomenon. The "brain" of the AOC could freeze, because in any case we are dealing with a mini-computer. Restart required. It is necessary to remove the terminal from the battery (any), i.e. de-energize the system and put it on again after a couple of minutes. If the alarm has started, you can fix the terminal, no - try rebooting 2-3 more times. If it does not work out, then we proceed to the next stage of repairing an alarm on a car - checking the fuses.
• Circuit breakers. If from the positive terminal of the battery (or from wires with a permanent "plus") there is a separate wire with a separate fuse block, check the fuse. Once we have started, at the same time we need to check the health and functionality of the main power consumers of the car (standard fuses): emergency gang, sound signal.During this test, the power supply is called by "minus" (this type of testing can be carried out if you know where the central AOC unit is located). In this case, the AOC is reset by the following method: remove the connector from the unit and reconnect it. If the beep sounds, it's okay.

If your efforts to repair alarms on a car are unsuccessful, then you will have to contact a car service, the cause of the malfunction turns out to be deeper.