Hino 258 issues

[solace-112]

Got a Hino 258 and after replacing the thermostat and head gaskets, it overheats and throws a CEL. The cooling fan never kicks in, and there are two similar plugs on the water pump housing that might be swapped. Looking for help diagnosing whether it's a sensor or wiring issue. How do I clear this? Thanks in advance

 

[Pistonbuster80]

Since they're identical let's start with the simplest solution, have you tried swapping them? The second thing I can think of is the fan clutch giving out, or a fuse or solenoid.

 

[I.robot]

Got a Hino 258 and after replacing the thermostat and head gaskets, it overheats and throws a CEL. The cooling fan never kicks in, and there are two similar plugs on the water pump housing that might be swapped. Looking for help diagnosing whether it's a sensor or wiring issue. How do I clear this? Thanks in advance

Probably got reversed during reassembly so the fan might never get the right signal to engage, even if the dash shows normal temp, check the part numbers or wire colors if you can, typically, the ECU sensor has more wires or a different plug shape