MTZ 952.2 - 3.2. Turn indicators

Appendix
MTZ series 900
263
3.2. Turn indicators
The blinking mode of lighting of the
signalling lamps (СЛ) of the turn
indicators is provided by the flasher
(KH2).
The functioning and correctness of
operation of the signalling lamps (СЛ) is
monitored by means of the two pilot
lamps (KЛ) of the tractor and trailer
located in the right block of pilot lamps
(HG1).
The circuit of the turn indicators is
supplied when setting the starter and
instrumentation switch (SA6) to the “I”
position.
On turning the arm of the steering-wheel-
mounted switch (SA7) clockwise or
counter-clockwise, respectively, the
following signal lamps of the turn
indicators light up:
• of the right side (wire Ч);
• of the left side (wire Г).
On setting the switch of the turn
indicators (SA7) to the ON position, the
current flows in the circuit and its value is
fixed by the electronic part of the flasher,
which specifies the operating mode of the
signalling lamps (СЛ) with the blinking
frequency of 90±30 cycles per minute as
well as the operating mode of the two
signalling lamps (KЛ) (of the tractor and
trailer) corresponding to the load in the
circuits.
The pilot lamps (KЛ) of the turn indicators
of the tractor and trailer are connected
permanently to the instrumentation supply
circuit (fuse (11)) and their second (minus)
lead shall be connected to the terminals "С"
(pilot lamps of the tractor, wire Ф) and "С2"
(pilot lamps of the trailer, wire Р) of the
flasher (KH2).
The voltage is supplied from the box (F1)
through (SA6) to the power supply relay
(K2) (terminal “85”) and further through the
terminal “87а” to the fuse (12) of the box
(F2) to the fault signalling switch (SB1)
flasher of the turn indicators (wire Ж,
terminal “49”), terminal “49а” and further to
the steering-wheel-mounted switch (SA7)
(wire 3).
The operating mode of the pilot lamps
depends on the operable state of the
signalling lamps and, respectively, on their
total current load created in the electric
circuit by the lit signalling lamps of the
tractor and trailer:
Variant 1: the tractor operates with the
trailer:
a) The signalling lamps are intact – both
lamps (KЛ) are lit (of the tractor and trailer);
b) One of the three signalling lamps (СЛ)
on the tractor or trailer is faulty: the pilot
lamp (KЛ) of the trailer is not lit while that of
the tractor continues blinking;
c) Two or free signalling lamps (СЛ) of one
side are faulty: neither pilot lamp (KЛ) is lit.
Variant 2: the tractor operates
without trailer:
a) The signalling lamps (СЛ) are intact: the
pilot lamp of the tractor is blinking and the
pilot lamp of the trailer is not lit.
b) One or both signalling lamps are faulty:
the pilot lamp of the tractor is not lit.
Deviation from the specified operating
mode of the pilot lamps can be caused by:
• using the signalling lamps with the rating
differing from the required one (lamps of
the type А12-21);
• poor contacts in the specified circuits.
• fault of the flasher (KH2).