Connect positive pole and negative pole of electric fan to positive
pole and negative pole of the battery .Electric fan shall be able to
rotate freely after the fan motor was connected with the battery.
Inspect the electric current with ampere meter
᷉
5.7-7.7A,see Fig
326
᷊
. If motor fails to rotate correctly, inspect the welding points
on the circuit. If it is still out of order after troubleshooting on
connection, the electric fan shall be replaced.
If coolant level falls below “low” mark, open the cover of water tank and replenish running water slowly to a level between
marks of “full” and “low” when the water tank is cold. If the replenishment occurs when water tank is in hot status, slowly
open water tank cover and replenish running water slowly to a level between marks of “full” and “low with wet cloth. Air
exhaust from water tank is usually an automatic process, and repair is required if any failure occurs.
V. Water filling and Air Exhaust
If under-cooled, parts like cylinder and cylinder head will be over-heated. Thus, replenishment of coolant is needed.
Most troubles come from the following three:
1. Engine overheat caused by under-cooling
If engine is overheated when coolant volume is adequate, it is possibly caused by pump failure, loose pump belt, fan failure
or thermostat failure, etc. Adequate trouble shooting measures are required.
II. Adequately cooled but engine is overheated
Abrupt overheat may be caused by sudden belt rupture, or bearing failure that disables the coolant pump. Thus, replace-
ment of belt and bearing is required. Other possible causes may be fan failure caused by fuse melting or electric failure that
disables the fan. Thus, replacement of fuse or repair of motor is required.
III. Abrupt overheat
IV. Inspection & maintenance on temperature-controlled electric fan
Fig. 326 Inspect the fan current value and its rotation
Section 3 Malfunction and Trouble shooting of Cooling System
Ampere meter
storage battery
149
Summary of Contents for JL481Q
Page 1: ......
Page 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...
Page 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...
Page 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...
Page 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...
Page 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...
Page 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...
Page 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...