BELARUS-1221.2/1221
В
.2/1221.3 Operating controls and instruments
27
The identification of the block outputs is given in Table 4.
Table 4
Output
Identification
1
to the terminal “–“
2
to the power supply unit “
+12В
”
3
to the board output “Parameter selection”
4
to the board output “Parameter value”
5
to the board output “Mode”
6
to the speed sensor BV2 (left wheel)
7
to the speed sensor BV1 (right wheel)
8
to the phase winding “W” of the alternator
9
to the instrument backlight lamps
1.5. Tachospeedometer diagnostics and troubleshooting
1. No instrument backlight:
Check the power supply wire connected to the output “9” of the 9-contact block of the
instrument (Fig. 3) – check if the backlight lamps are intact.
2. Jerking and jumps of the pointer of the engine rotational speed indicator over
the dial:
poor contact on the alternator terminal and, therefore, poor signal from the
phase winding of the alternator. Repair.
3. Jerking of t
he pointer and understating the reading of the engine rotational
speed:
- Check and adjust the tension of the alternator driving belt.
4. Over- or understated readings of the engine and PTO’s rotational speeds (with
the nominal movement of the pointer):
- Check the correctness of programming the instrument according to the engine model
(parameter “D”): (see item 1.3);
5. The counter of astronomical hours of the engine running fails to accumulate
the operating time:
Check the connection of the wire to the contact “8” of the instru-
ment block and the presence of the frequency signal from the phase winding of the al-
ternator.
6. Over- or understated readings of the tractor speed:
- Check the correctness of the instrument programming according to the rolling radius of
the rear wheels (Rk) (see item 1.3);
- Check the correctness of the programming according to the number of teeth of the
half-axle pinion (Z) (see item 1.3).
7. No readings of the tractor motion speed:
Check the presence of signals from both
the speed sensors (BV1, BV2).
8. The readings “02…07” km/h appear on the instrument indicator when the tra
c-
tor is moving:
- the numbers “02…07” and, 12 seconds later, “0” appear from the right side of the
scale – no signal from the right speed sensor (BV1).
- the numbers “02…07” and then “0” appear from the left side of the scale – no signal
from the left speed sensor (BV2).
Summary of Contents for 1221.2
Page 1: ...BELARUS 1221 2 1221В 2 1221 3 1221 0000010РЭ OPERATORS MANUAL 2009 ...
Page 290: ...BELARUS 1221 2 1221В 2 1221 3 Supplement 293 Electrical scheme of tractor connections ...
Page 291: ...BELARUS 1221 2 1221В 2 1221 3 Supplement 294 Variants of tractor connections ...
Page 293: ...BELARUS 1221 2 1221В 2 1221 3 Supplement 290 826 3805010 instrument board scheme ...
