just recieved new ecm and installed it, fan still runs and wont shut off.i read somewhere that there was a resistor and wire harness that had to be used on some 700's because the thermal switch in the head was not syncing with the thermostat. What is the resistance hot and cold on the thermal switch and what is the thermostat temp supposed to be .It's like the thermostat keeps the temp higher than the thermal switch ,so the switch never sends the message to the ecm to shut off.New Rad new thermostat new hoses new ,new ecm,new thermal switch,new antifreeze ,checked pump impeller ,new antifreeze ect .

 

Fan on at 195 degrees.Fan off at 180 degrees.Hot light at 215 degrees. Manual does say if the sensor(I know it's new) or it's wiring has a malfunction,the fan defaults to on. Same thing that should happen if you turn the key on and remove the sensor wire. The fan should kick on then. Read chapter 10 page 3 as there are some tests you can try. I do remember on one model 800 that I had to wire in a 33 ohm resistor on the sensor wire on several of them because of this same reason.They didn't have the crappy ecm module though that I'm still leery about.

 

my thermostat is open at 180 marked on thermostat [quad logic thermostat that replaces part 7052352 and 7052380 could my problem be the thermostat keeps the engine at 180 thus the fan never cuts off after it warms up .what is the temps on the oem thermostat .when i disconnect the wire on the switch the machine flashes hot and fan cuts in .

 

Hot light is supposed to flash and fan is supposed to come on when you pull the sensor wire. Sounds like the aftermarket thermostat is your problem then.

 

do you know what the oem thermostat temp is .its $90 here and i already spent 40 on the quad logic one and about $500 on everything else just trying to figure this out and now looks like i will be replacing new items ,really appreciate the imput,thanks

 

You might see if you can find a 195 degree t-stat at an auto supply first.Don't know if they'd carry one but no harm trying. Take your old one for comparison. Cheapest oem t-stat I've found is here.7052352 Polaris Thermostat $39.27 - 2WheelPros Being where you are prices may be higher just for shipping?

 

i am just not understanding. If my thermostat keeps my engine at a constant 180+-1 degree and my switch tells the fan to shut off at 180 +- 1degree .when does the system ever get cool enough for the thermal switch to shut the fan off.Will the thermostat temp always keep the temp at or above the shutoff temp on the fan?

 

My fan stays running after all the heat is removed by the fan and the air is cold blowing through the rad and the hoses have cooled slightly . i figure the thermostat is in the closed position and keeping the 180 water in the head . i can feel the temp rise and fall with the thermostat opening and closing .

 

Only thing I can say at this point is to try the oem thermostat. If the fan still won't shut off,then either a wiring problem somewhere or a problem even in that new ecm module that controls the fan and also hot light.

 

will order the oem thermostat thanks again for your time and knowledge ,George