The wiper system is designed to wash and clean windshields in order to ensure the safety of the car.
It includes electric wipers 27.5205 and windshield washers 1112.5208-01.
The electric windshield washer is controlled by a rocker switch and has an electric pump built into the washer reservoir.
The pump is powered by a 10A fuse.
The electric wiper ensures the operation of the brushes in two modes and their stop in their original position. It includes a gearmotor, powered brushes and a three-position switch.
The voltage to the gearmotor is supplied through the relay of the heater electric motors, so the wiper can be turned on when the instrument and starter switch is turned on in position "1".
The washer and wiper rocker switches are located to the right of the steering column on the switch console.
When the washer switch is turned on, current passes through the pump motor.
“+“ batteries, starter terminal, starter relay pin B —► ammeter, connector pin 1G, 60 and 30A fuse box pins 1G and 57 —► 10A fuse —► switch break contacts —► washer motor —► housing —► “ground” switch — “—“ battery. The electric motor drives a pump that supplies washer fluid through flexible tubes to two single-jet jets and then to the windshield.
The wiper motor gear motor has three brushes: one negative and two positive.
The negative brush is connected to the car body, and the positive brushes are supplied with voltage from the on-board network through the wiper switch.
When voltage is applied to different positive brushes, different frequencies of rotation of the motor armature and, accordingly, different modes of operation of the wiper blades are provided.
The design and replacement of the windshield wiper is described in the article: Design and replacement of the KAMAZ windscreen wiper
The wiper works in the following way:
- - when the instrument and starter switch is set to position "1", the heater motor relay is activated, since voltage is applied to its winding from the short circuit output of the instrument switch and starter through a 7.5 A fuse;
- - when the relay is triggered, the voltage from its output 30 is supplied to output 87 and then through a 10 A current fuse to output 110 of the gearmotor connector, gearmotor fuse, output 110A of the gearmotor, output 110A of the switch;
- - in position "1" of the wiper switch, the voltage from its output 110A is supplied to output 111 and then to one of the positive brushes of the gear motor (top in the figure). At the same time, current begins to flow through the electric motor, since its negative brush (lower in the figure) is constantly connected to the car body; the electric motor through the gearbox and the drive provides the reciprocating motion of the brushes with a certain frequency;
- - when the wiper switch is set to position "2", the voltage from its output 110A is supplied to output 112 and then to the second positive brush (in the figure on the left); in this position of the switch, the wiper operates with a greater frequency;
- - when the wiper is turned off, the brushes return to their original position using the limit switch S1 of the gearmotor. The state of the circuit breaker contacts (see fig. 2) is shown for the initial state.
When the brushes move, the contacts switch to another position. Therefore, when the wiper switch is set to the neutral position, the movement of the brushes continues to its original position, since in this case the voltage is supplied to the gearmotor electric motor as follows;
- output 110 of the gearmotor -► fuse F1 -► closed (lower) contacts of the limit switch -► outputs 111B of the gearmotor and switch -► outputs 111 of the switch -► output 1114 of the switch -► outputs 111 of the switch and gearmotor -► positive brush of the gearmotor ( top).
When the wiper blades reach their original state (bottom of the windshield), contact
the limit switch acts return to its original state, open the power supply circuit of the gearmotor and the wiper blades stop.