I have a 98 sportsman 500. Ive had some electrical issues. I want to check fan and temp switch to make sure they r ok. Does any body know how to check sensor? Whats the ohm it should be if its ok? The fan i can just put 12v to it and it should spin

 

Just jump 12 volts to the fan motor to see if it's ok. You can test the radiator sensor by just unplugging the connector and checking ohms resistance on the two wires. Remember this reading. Take a hair dryer(wouldn't advise using a torch) and hold on the sensor awhile,then check ohms resistance again. Resistance should be lower. Once the sensor gets hot enough,it completes the ground path for the fan to kick on. If there is no reading on the sensor, or erratic, then it needs to replaced. Faulty sensors were the most common problem on fans not kicking on,running hot. Plus not a bad idea to check the fan circuit breaker in the sealed pouch under the front panel also. If the circuit breaker terminals are corroded you can replace it at any auto supply. Same thing on the hot light sensor sensor on the engine. Check resistance to ground,then heat it up,resistance should drop if it's ok.