Polaris Sportsman 400, Service Manual

Page: 367 / 381

ELECTRICAL
10.33
COOLANT TEMPERATURE SENSOR TEST (HOT LIGHT)
With the ignition switch (and engine stop switch) “ON”, power is delivered to the hot light via the Red/White wire.
The Blue/White wire (ground) out of the light socket is connected to the coolant temperature sensor on the cylinder
head. In normal operating conditions, the temperature sensor is non-conductive (open). If engine coolant reach-
es the specified temperature, the sensor becomes conductive completing the ground path for the light.
With engine cold, disconnect lead and measure resistance of sensor between connector terminal and ground.
There should be no continuity or very high resistance (megohms). To test the “ON” temperature, heat the switch
in a water bath to the temperature shown in table below. The switch should become conductive (low resistance)
at indicated temperature. Do not immerse switch past the threads or allow switch to contact container when heat-
ing.
Hot Light On 221
°
F (105
°
C)
HOT LIGHT CIRCUIT TEST
Disconnect temperature sensor wire lead and short it to ground on the cylinder head. Turn key and auxiliary switch
to “ON” position. The hot lamp should come on. Check the bulb and related wiring if the lamp does not illuminate.