Service manual

ManualsBrandsEton ManualsChassisVECTOR 250 - SERVICE

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12-3 Troubleshooting

Engine temperature too high

• Water thermometer or temperature sensor malfunctioning.

• Thermostat stays closed.

• Insufficient coolant.

• Water hose or jacket clogged.

• Fan motor malfunctioning.

• Radiator filler cap malfunctioning.

Engine temperature too low

• Water thermometer or temperature sensor malfunctioning.

• Thermostat stays open.

Coolant leaking

• Water pump mechanical seal loose or malfunctioning.

• O-ring worn or damaged.

• Water hose broken or worn.

12-4 Troubleshooting Flowchart

Temperature indicated is too high:

• Stop the engine and let it cool completely. Open the radiator cap and check the

radiator coolant.

o Coolant level low: Refill radiator with coolant and check for leaks

• Turn the main switch on and make sure the water temperature indicator is at zero

o If not: Check for current going to the thermostat. It must be at least 6V.

 If not: Replace the thermostat

 If so: Check for shorts or grounding in the circuitry

• Open the radiator cap and very gently apply the throttle. Check if the coolant is

circulating.

o If it isn’t: Stop the engine and remove the water pump cover. Restart the

engine and inspect the pump rotation.

 If it rotates, there is a clog in the water hose.

 If it does not, repair or replace the water pump.

• Close the radiator cap. Test the thermostat current for variance as the temperature

rises.

o If it does not detect the temperature change, replace the thermostat.

• Allow the engine to run at 3-4000 RPM. Inspect the cooling fan.

o If the fan was not operating, check the thermal switch current for changes in

voltage (12 Æ 0V).

 If the voltage does not change, replace the thermal switch.

 If it does, test the fan directly by attaching a 12V battery to the

terminals on the fan. If the fan does not operate, replace it.

• Keep the engine running at 3-4000 RPM. Inspect the coolant flow in the reserve tank.

• Remove the thermostat from its holder and check its operation directly with water. If it

does not operate correctly, replace the thermostat.

• Refill the coolant reservoir and ensure there are no twists, bends, or air bubbles in the

coolant tube.

• To bleed air bubbles out, open the radiator cap while the engine is cool and start the

engine. Gently press on the hose to bleed. Apply throttle and check if the surface of

the coolant appears stable. Repeat bleeding if necessary.