General information and precautions

General information

1. Engine electrical systems include all ignition, battery charging and engine starting components. Since their function is related to the operation of the engine, these components are presented separately in this chapter. And electrical devices of the body equipment, such as lighting devices, control devices, etc., are presented in chapter 12.

Precautionary measures

2. When working on the electrical system, always observe the following precautions:

• A) Be extremely careful when servicing the electrical components of the engine. They can easily be damaged if not properly controlled, connected or handled.
• b) Never leave the ignition on for a long time if the engine is not running.
• V) Do not disconnect the battery wires while the engine is running.
• G) Observe the polarity when connecting the wire from the battery of another vehicle in case of starting from an auxiliary power source (see "Auxiliary Start").
• d) Always disconnect the negative cable first and connect it last. Otherwise, the battery can be short-circuited by the tool when the wire clamps are released (see fig. 1.2). Before starting work, it makes sense to read the information "Safety first".

Disconnecting the battery

3. Some vehicle systems require constant power supply due to continuous operation (like a clock) or saving the parameters of the electronic memory (such as the BEU engine management system), which are erased when the battery is disconnected. Therefore, whenever you need to disconnect the battery, first of all consider the following guidelines:

• A) On vehicles with a central locking system, you should always remove the key from the ignition and carry it with you, so that it does not remain in a car locked with this system in case this system is accidentally triggered while connecting the battery!
• b) The ECM of the engine management system loses the information stored in the memory when the battery is disconnected. This applies to the parameters of idling and other operating conditions, as well as codes of detected faults. When trouble codes appear, indicating a malfunction of the system, the car must be taken to dealers for troubleshooting on special diagnostic equipment (chapter 6). In any case, when the battery is disconnected, the parameters relating to the idle speed control, as well as other operating parameters, must be re-entered into the electronic memory of the control device. The BEU performs the input of such parameters on its own, but before they are entered, the engine may experience starvation, interruptions or unstable idling or not achieve its characteristics. To enter these parameters into the BEU in the learning mode, start the engine and bring it to the operating mode at a speed that has minimal differences from the idle speed. Keep it in this mode until it warms up to normal operating temperature, and then let it run at 1200 rpm for about two minutes. After that, you need to make a trip to the distance that you require. When you have driven about eight km using the various driving modes, the learning process is complete.
• V) If the battery is disconnected while the alarm system is on or activated, the system will remain in the same mode it was in when the battery was disconnected. The same thing happens with the immobilizer (if available) engine.
• G) If there is an on-board computer, all information stored in memory will be lost.
• d) If an audio unit with a special code is installed on the car, if this unit and/or battery is disconnected, the unit will cease to function after it is connected until the appropriate code is entered. Detailed information on this, depending on the block and year of manufacture, is presented in the Ford Audio Manual, which is supplied with a new car, and the code is recorded on the radio passport and / or code label. Before disconnecting the battery, make sure you have the required code. For safety reasons, this procedure is not described in this manual. If you do not have a code or a description of the procedure, but you can prove your ownership and have a legitimate reason to obtain such information, contact your dealers who can help you.

4. To eliminate the above problems, devices with the function "save memory" (or "save code"). They have some differences. But usually, such a device is inserted into the cigarette lighter socket and connected by its wires to a spare battery. The vehicle battery can then be disconnected from the electrical system. At the same time, the device "save memory" provides power to the audio unit (to save the code) and BEU memory, as well as DC power circuits such as those used in watches. At the same time, the battery (spare) protected from the influence of a possible short circuit during work.

Warning: Some of these devices allow a mode where many vehicle systems will be powered and operational after the battery is disconnected. If you are using a device "save memory", then first make sure that the circuit you will be servicing is really de-energized!