Polaris ATV Forum banner

Trailboss 330 Hot Engine plus fan running

11K views 4 replies 3 participants last post by  petsetas 
#1 ·
from one day to the other i have this problem now. Indicator on speedometer blinks about hot engine plus then fan running all the time. quad seems to work normal.
searched a bit around in the net and found that for many ppl the problem was solved by changing the control module (4011088, i got the new 1 with part nr. 2203349)
ordered that 1 + installed it but the problem is still there. connections + cables seem to be all fine, also checked the sensor at the cooler.

any ideas? what exactly are both blackboxes responsible for? do i need to change the other 1 as well?
any chance to get a decent circuit layout from somewhere?

any help is very very welcome folks, thx a lot!
 
#5 ·
problem solved. checked the thermistor and it was shorted. should have done that before ordering a new ecm unit :(
made the mistake and trusted a friend who said he checked it..

keep in mind guys that if the thermistor is bad (either shorted or always open) the ecm will have the fan ALWAYS ON + hot check engine flashing on display.
ecm needs a resistance from the thermistor to work proper. shorted or open are no valid values/ i guess for safety reasons the ecm set the fan ON and display flash so it wont overheat.
You can easy test that by simply unplugging the thermistor licking 1 finger of yours and placing it over the contacts in the plug. u will need to extend the connections from the plug a bit cuz otherwise u wont be able to reach them with your finger. just stick a lil bit of cable in both contacts and then short it with your wet finger. U will see the fan will instantly stop running and the display will look normal again.

typical readings from a good thermistor should be ~ 100k Ohm @roomtemp and around 1500 Ohm when hot.

Cheers folks
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top