MTZ 952 - Page 246

Appendix
MTZ series «900»
246
1.1. Troubleshooting of the power
supply system
A. No voltage in the on-board power
system after setting the battery
disconnect switch QS1 to the on
position:
• Check the intactness of the fuse F1;
• Check the contacts at the place of
connection of the wires to the SB
terminals;
• Check the integrity of the circuit
from the storage battery to the
fuse.
B. No battery charging after starting
the engine:
• Check the condition of the
alternator driving belt and voltage
regulation;
• Check the intactness of the fuse F1;
• Using a voltage indicator, check the
controllable voltage of the
alternator (Fig. 1), which shall be
14.2 – 15.2 V;
• Check the reliability of the contacts in
the circuit from the alternator to the
voltage.
Note: The check shall be performed at
the rated rotational speed of the
engine and working headlights on.
C. The storage batteries are
systematically undercharged:
• Check the value of the controllable
voltage (Fig. 1), and, if it is below the
allowable value, replace the IVA;
• Check the technical condition of the
storage battery;
Fig. 1. Checking the controllable voltage value: 1
– alternator G1; 2 – voltage indicator.
• Check the reliability of the contacts in
the connections of the terminals of the
wires from the alternator to the storage
battery having excluded the possible
increase of the resistance at the
terminals due to loosening of their
fastening or oxidization.
D. On the tractors with the power
supply system with the voltage of
12/24 V (Fig. 2) and voltage converter
UZ1, the left storage battery is not
charged;
• Check the integrity of the fuse and
reliability of its fastening to the voltage
converter body ПН-191-375901 (ПН
14/28 V 8 A); if the fuse (20 A) is blown
off, the pilot lamp of the voltmeter in the
combined meter lights up;
• Check the fastening the wires to the
terminals.