12.4. Safety locks and fusible inserts - the general information
The assembly block of safety locks / relay (No. 2) located in a motive compartment
Saloon assembly block of safety locks
Various combinations of safety locks, breakers of a chain and fusible inserts are applied to protection of contact chains of electric equipment of the car. Assembly blocks, are installed under the dashboard and in a motive compartment of the vehicle (see the illustrations Located in a motive compartment the assembly block of safety locks / relay (No. 2) and the Saloon assembly block of safety locks).
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 glued to a cover of the last, from its internal party.
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 (see an illustration the Saloon assembly block of safety locks).
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.
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.
On the Infiniti QX4 models fusible inserts are placed in the assembly block of safety locks located in a motive compartment (see the illustration Located in a motive compartment the assembly block of safety locks / relay (No. 2)).
For replacement of a fusible insert disconnect a negative wire from the battery and, having pulled failed an element, take it from the landing nest.
If the stereosystem established on the car is equipped with a security code before disconnecting the battery make sure that you have the correct combination for input of the audio system in action!
Before establishing into place the failed fusible insert new it is necessary to find out and remove the cause of the overload taking place.