TGB Blade 250 ATV Quad Service Repair Manual, Page 134Get this manual
12COOLING SYSTEM Trouble Diagnosis for Cooling System
The temperature indicated is too high
Water leaking problem
AStop and waiting for the engine is completely cooled down, open cap to check the capacity of coolant in radiator
A1 .Refill the radiator with coolant then check for any leakage?
BTurn on main switch and check the water temperature indicator back to zero?
B-1Measure thermo unit to confirm voltage 6VT ?
Replace thermo unit