My Legacy will idle and warm up and thermostat opens, Fans come on and cycle and all is good. Drive it around the block, The fans come on and stay on, Radiator gets cold thermostat closes and the fans keep running but the engine does not over heat????

Coolant temp sensor is bad or the fan relay is stuck.

Fan relay is easy. Just smack it with the handle of a screwdriver when the fan seem to be "stuck on" and that should rattle it loose so the fan will turn off.

Coolant temp sensor is bad

 

 

That was my first thought.

I just replaced the Temp sensor, Thats not it it's still doing the same thing. The fans only come on and stay on while i'm driving.

If you are running the defrost setting on the heat then that will kick on the AC compressor and also the fans. They will run as long as the AC is running to dry the defrost air.

 

GD

No defrost, No heat, no A/C the fans come only while driving and stay on. If the car is sitting still the fans will cycle normally and the thermostat stays open. Oh, and it only happens when its cold outside (below 40)

hrmmmm For giggles chek the alt output.

 

What is the temp outside. WHat happens if you disconnect the fan switch.

 

Is the radiator flowing properly

hrmmmm For giggles chek the alt output. Don't know, but I'll check

 

What is the temp outside. 37 WHat happens if you disconnect the fan switch. Have not tried that yet

 

Is the radiator flowing properly

Yes, It's pretty new and I checked.

41 degrees, Main fan unplugged, Main fan fuse removed sub fan runs all the time !!:mad::mad:

41 degrees, Main fan unplugged, Main fan fuse removed sub fan runs all the time !!:mad::mad:

 

Sounds normal to me.

 

Did you replace the coolant temperature sensor or the radiator switch?

 

FYI,the VSS also controls the fans.(turns them off above a certain speed, I presume)

I replaced the Coolant temp switch, Where is the radiator switch located? there is nothing screwed into my radiator. VSS ??? Translate to English please. lol

Section 2-5 of the ej22 manual here may be helpful.

http://www.finleyweb.net/JonsStuff/SubaruDocumentation.aspx

 

I don`t think you have a rad switch after all.

The poorly written factory manual states there is one and then clearly shows that there isn`t.

 

VSS=vechicle speed sensor

Its interaction w/the fans is probably more complex than I originally presumed.

 

Gleaning info from an incorrect FSM,it seems fan operation is governed by which of 3 road speed brackets the car is in and wether accellerating or decellerating as well as coolant temperature.

I have the factory Subaru Repair manuals and they don't show any radiator sensor.