98 pete 3406e engine fan wont turn on for temperature

the 9ns is the prefix and what I needed. You have a three wire coolant temp sensor should still be located top of t-stat housing. the wires run back to the ecm. You can ohm out the wires from the sensor connector to ecm plug. pin #14 coolant temp. #30 sensor common. and #36 5 volt.

 

pin 28 on the oem plug (the black plug) is output for the fan.

 

check the fuse panel option 4. also I believe behind the speedo panel you will find 4 fuses and 3 relays check the fuses.

 

5ek 3406e .. I'm having same issue. Fan won't come on to cool . I get warning light and beeper for high temp. I have to switch fan on in cab then engine cools down. I have 2 one pin sensors on t-housing and a 3 wire with a plug which i think goes to ecm, in the front of the t-housing. Which one controls the fan ??

 

Hi, Did you get it resolved. I'm having the same issue with my 5EK 3406E. At least I think I have a 5EK, dealer says original motor was a 6NZ but the mechanic who replaced my water pump and thermostat swore that the engine was changed and that I now have a 5EK. Cannot find the serial number after several paint removing attempts.