14.4. Protection of electric contours

Various combinations of safety locks, fusible inserts and breakers of a chain are applied to protection of contact chains of electric equipment of the car. Assembly blocks, are installed in interior of the car and in a motive compartment of the vehicle.

Safety locks

General information

Each separate safety lock is used for protection of any concrete electric contour or at once several contours. The ID card of placement of safety locks in the assembly block is usually applied on a cover of the last, from its outer side.

In assembly blocks the safety locks of a compact design equipped with bayonet contact plugs, and which, if necessary, are easily taken by fingers from the nests in the block are located. At refusal any of consumers of the electric power first of all it is always necessary to check a condition of the corresponding safety lock. Turn a key in the ignition lock in position of ON and by means of a lamp sampler probe open plugs of each of safety locks. If the lamp lights up at connection to each of plugs, therefore, a safety lock as it should be. If tension takes place only from giving of food, so the safety lock fused. Let's notice also that usually the case of a safety lock is manufactured of transparent plastic through which it is easy to define a condition of a working crossing point.

When replacing of the fused safety lock strictly you watch that the established replaceable corresponded on the type which left from an element. The safety locks calculated on various nominal current physically can differ in nothing from each other, without being at the same time interchangeable. Each of electric chains has various working parameters and needs various degree of protection therefore replacement of the safety lock calculated on a certain current, not corresponding to it in parameters is fraught with the most serious consequences (up to fire emergence). Working parameters of a safety lock (nominal current) are usually designated on its plastic case.

If the new safety lock at once after installation also fails, it does not make sense to make its further replacement, - before it is necessary to reveal and remove the cause of an overload in a chain. In most cases that appears the short circuit of a connecting electrical wiring caused by damage of its isolation.



1. Schemes of an arrangement of safety locks in assembly blocks are presented in Specifications to the present Chapter.
2. In a motive compartment the assembly block settles down in close proximity to the rechargeable battery, in salon - at the left under the dashboard.

3. Uncover the corresponding assembly block.

4. By visual survey reveal the failed safety lock and by means of a special clip take it from the landing nest.

5. Study a condition of contact plugs in a reception nest of the assembly block, remove oxidation traces, replace defective plugs.

6. Establish to the place of the failed safety lock replaceable, corresponding original in parameters.

The set of spare safety locks is usually stored in the saloon assembly block.

Fusible inserts

General information and replacement


1. Fusible inserts are used for protection of chains in which for any reason usual safety locks, such as a contour of system of ignition, and also for power chains in which the high-ampere current circulates cannot be used.
2. The main set of fusible inserts is mounted in a motive compartment near the rechargeable battery. The second group is placed in the assembly block of safety locks/relay located in the neighbourhood.
3. At an exit of a fusible insert out of operation extremely to find out the cause of an overload in the corresponding electric contour.
4. The failed fusible inserts of usual type are not subject to recovery repair. Track that the replaceable element completely corresponded on the rating data failed.

Chain breakers

General information

Breakers of a chain are used for protection of such components of system of onboard electric equipment as head headlights and electric motors of the drive of window regulators, activators of door locks, etc.

On some models after operation breakers revert to the original state automatically. If the overload which caused shutdown of the breaker had not incidental character, it is necessary to check a condition of the corresponding contour immediately. After malfunction elimination the chain breaker enters the normal mode of functioning again. Sometimes return of the breaker to the working condition should be made manually after elimination of the reason of an overload.