We deal with the fuse box VAZ 2105

One of the key components of the electrical circuit of the VAZ 2105 car is the fuse box. Many problems with electrical equipment that arise during the operation of the vehicle are associated with this particular node. Motorists, as a rule, are engaged in maintenance and diagnostics of malfunctions of the fuse box on their own.

Fuses VAZ 2105

The purpose of the fuses used in the VAZ 2105 car does not differ from the function of any other fuses - protection of electrical circuits from short circuits, sudden power surges and other abnormal operating modes. Fuses VAZ 2105, which can be cylindrical or plug type, are mounted on the same block with the relay. The mounting block can be located under the hood or in the car.

The operation of the fuse is based on Ohm's law known from school: if resistance decreases in any part of the electrical circuit, this leads to an increase in current strength. If the current strength exceeds the allowable value provided for this section of the circuit, the fuse blows, thereby protecting more important electrical appliances from failure.

Block under the hood

In most VAZ 2105 models (with the exception of the earliest samples), the fuse box is removed from the passenger compartment under the hood: you can see it under the windshield, opposite the passenger seat.

If the mounting block is located under the hood of the VAZ 2105, then you can see it under the windshield, opposite the passenger seat

Table: which fuse is responsible for what

Fuse	Rated current, A	What protects
F1	10	back light, electric heater, relay winding and signaling device for heating the rear window
F2	10	e / d windshield washer, e / d and headlight washer relay, windshield wiper relay
F3	10	spare
F4	10	spare
F5	20	rear window heating circuit and heating relay
F6	10	cigarette lighter, socket for portable lamp, clock
F7	20	horn circuit, radiator cooling fan circuit
F8	10	direction indicators, breaker relay, signaling device of indexes of turns at the alarm system, alarm switch
F9	7,5	fog lights, generator voltage regulator (if the machine uses a G-222 generator)
F10	10	signaling devices: direction indicators, fuel reserve, handbrake, oil pressure, emergency state of the brake system, battery charge, carburetor air damper cover; indicators: turn (in the mode of direction indication), fuel level, coolant temperature; direction indicator relay; winding relay for electric fan; voltmeter; tachometer; pneumatic valve control system; fan thermal switch; excitation winding of the generator (for generator 37.3701)
F11	10	interior lighting, stop signal, trunk lighting
F12	10	high beam on the right headlight, headlight washer relay (high beam)
F13	10	high beam on the left headlight
F14	10	front clearance on the left block headlight; rear clearance on the right lamp; room lighting; engine compartment lighting
F15	10	front clearance on the right block headlight; rear clearance on the left lamp; instrument panel illumination;
F16	10	dipped beam on the right block headlight, headlight washer relay (low beam)
F17	10	dipped beam on the left headlight

In addition to the fuses indicated in the table, there are 4 spare fuses on the mounting block - F18-F21. All fuses are color-coded:

• 7,5 A - brown;
• 10 A - red;
• 16 A - blue;
• 20 A - yellow.

The color of fuses VAZ 2105 depends on their rated operating current

How to remove the mounting block

To remove the fuse box, you will need a 10 socket wrench. To dismantle the fuse box, you must:

1. Disconnect the negative battery terminal.
2. Disconnect plug connectors in passenger compartment.
   

   Before removing the unit, you need to disconnect the plug connectors in the cabin under the glove box
3. Unscrew the nuts of the fixing bolts (in the cabin under the glove compartment) with a 10 wrench.
   

   After that, you need to unscrew the nuts of the mounting bolts of the block
4. Push the fuse box into the engine compartment.
5. Detach connectors underneath the fuse box.
   

   Next, you need to disconnect the plug connectors located at the bottom of the fuse box
6. Remove the block from its seat.
   

   After all the connectors are disconnected, the unit can be removed from the seat

The connectors on the interior side and in the bonnet are colour-coded. The connector sockets on the fuse box are marked in the same color (in the form of colored circles). This is done so that when assembling the block, not to confuse which connector was connected to where. If there is no color marking on the block, you should make it yourself (for example, with a marker). A new or repaired unit is installed in place in the reverse order of dismantling.

The old and new fuse blocks are interchangeable. If instead of the old one you want to install a new type of block, you will not need to make any changes to the design of the car. The difference between the blocks is only in the type of fuses used: on the old - cylindrical, on the new - plug.

Repair of the mounting block

If there are interruptions in the operation of the electrical equipment of the car, first of all it is necessary to check the fuse box. If one of the fuses fails, it is strongly not recommended to replace it with a fuse capable of withstanding current higher than the rated current.. Such a fuse can cause wiring, lamps, motor windings, or other electrical equipment to burn out.

When repairing the fuse box, certain rules must be followed. For example:

• if any fuse is blown, you need to try to find the reason for this, that is, check the entire section of the circuit for which this fuse is responsible;
• if you installed additional electrical equipment in the car, you need to recalculate the rated current that the fuse responsible for this section of the circuit must withstand. To do this, it is necessary to divide the total load (power) of consumers of this section of the circuit by the value of the on-board voltage (12 V). The resulting figure must be increased by 20–25% - this will be the required value of the fuse operation current;
• when replacing the block, you should pay attention to whether there are jumpers between the contacts of the old block. If there is, then on the new one you need to do the same.

If there are jumpers on the removed fuse box, the same ones must be installed on the newly installed fuse box.

If it is possible to choose between blocks of the old and new type, you should definitely install a new type of mounting block: tighter fuse contacts on such a block will immediately save you from many problems associated with a loose fit of fuses in old type blocks.

Repair of the mounting block most often consists in replacing fuses or restoring a burnt track. You can check the fuse with a multimeter: instead of a failed fuse, install a new one.

Replacing a burnt track

In some cases, when the load in the circuit increases, it is not the fuse that burns out, but one of the tracks of the block. In this situation, you need to assess the degree of burnout: if the damage is minor and the rest of the components of the block are not affected, such a track can be restored. This will require:

• soldering iron;
• lead and rosin;
• wire 2,5 sq. mm.

The repair of the track is carried out in the following sequence:

1. We clean and degrease the damaged area.
2. We remove burnt and non-recoverable fragments of the track.
3. We prepare a piece of wire of the required length, remove the insulation along the edges and process it with a soldering iron and solder.
4. In place of the burnt track, solder the prepared wire.
   

   In place of the burned-out track, a piece of wire with a diameter of 2,5 square meters is soldered. mm

If the tracks have multiple damage, it is easier to replace the entire block.

Video: how to repair a blown fuse box track

Repair of the fuse box on the VAZ 2105-2107

Mounting block in the cabin

In the first VAZ 2105 models, the fuse box was located in the passenger compartment. Such a block can still be seen today in some "fives" under the instrument panel next to the left door. Each of the fuses on the block located in the passenger compartment is responsible for the same section of the electrical circuit as the corresponding fuse on the block located under the hood.

How to identify a blown fuse

If there are problems with any group of electrical equipment in the car, the likelihood that the fuse is high, but not one hundred percent. To make sure that the fuse has failed, sometimes an external examination is enough: if there are burn marks on its body, most likely the fuse has burned out. This method of verification is quite primitive, and in this case it is better to use a multimeter that allows you to diagnose a malfunction:

• by voltage;
• by resistance.

In the first case, you need:

1. Set the multimeter to voltage measurement mode.
2. Turn on the circuit to be tested, such as lighting, stove, etc.
3. Check for voltage at the fuse terminals. If there is no voltage at one of the terminals, the fuse must be replaced.

In the second case, the multimeter is switched to the resistance measurement mode, after which the instrument tips are connected to the removed fuse. If the resistance value is close to zero, the fuse needs to be replaced.

If the resistance value is close to zero, the fuse needs to be replaced.

Dismantling and repair of the unit

The fuse box located in the passenger compartment is removed in the same sequence as that installed under the hood. It is necessary to unscrew the fasteners, remove the connectors and remove the block. Just as in the case of the block located under the hood, the repair of the mounting block installed in the cabin consists in replacing the fuses and restoring the tracks.

If the fuse blows on the road and there is no spare on hand, you can replace it with wire. But at the first opportunity, the wire must be removed and a nominal fuse installed instead.. The fuse layout is usually shown on the inside of the mounting block cover.

It should be remembered that there are several types of mounting blocks that outwardly do not differ from each other. The differences are in the wiring of the tracks. When replacing a block, make sure that the markings of the old and new blocks match. Otherwise, the electrical equipment will not work correctly.

I changed the mounting block in the VAZ 2105 about six months ago. When I changed, I did not know that there are several types. The sellers at the car market claimed that there is only one type, and since my old one completely crumbled, I had to take what was.

With the new block, two problems appeared at once: the wipers stopped working (this problem was solved by throwing a jumper from the first fuse to the second). The second problem (and the main one) is when the car just stands with the engine turned off, it discharges the battery (the charging wire, if it matters, is inserted into 3 chips 1 socket, I don’t know how to say otherwise, I almost don’t rummage in auto electrics. Completely charged in about 8 hours, it discharges to 0. The third problem (not so important) is that the turn signal repeaters disappeared. I went to an auto electrician, he just threw up his hands, looked at the panel and could not do anything. I knew this would happen, so I have nothing to compare it to.

A pedestrian

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Old style fuse block

In old-style mounting blocks, cylindrical (finger-type) fuses are used, which are installed in special spring-loaded connectors. Such connectors are not distinguished by reliability and durability, as a result of which they cause a lot of criticism from motorists.

The old-style VAZ 2105 mounting block uses cylindrical fuses

Each of the 17 fuses located on the old-style mounting block is responsible for the same groups of electricity consumers as the corresponding fuses on the new-style block (see table above). The difference is only in the value of the rated current for which the cylindrical fuses are designed. Each plug-in fuse (on a new type block) with a rated current:

• 10 A corresponds to a finger-type fuse with a rated current of 8 A on an old-style block;
• 20 A - 16 A;
• 7,5 A - 8 A.

Maintenance and repair of the VAZ 2105 fuse box in most cases does not cause difficulties for motorists. To independently determine the malfunction of the mounting block and eliminate it, even a little driving experience is enough. For reliable operation of electrical equipment, it is important to use fuses with the parameters specified in the technical documentation.