Fan not working. 98 w900

Discussion in 'Kenworth Forum' started by irishluck09, Apr 24, 2022.

  1. irishluck09

    irishluck09 Light Load Member

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    I'm doing some maintence today after my first week in my new truck. My fan doesn't seem to come on automatically or with the switch

    First question is what temp should the fan kick on at?

    2nd question is I read somewhere that if that truck is off, that the fan should not move and if it does, then it's likely bad. Is this true? Because my fan clutch is free spinning with the truck off.
     
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  3. Big Road Skateboard

    Big Road Skateboard Road Train Member

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    Should kick on 210-218. Second question, that means nothing. Can you post a pic of the fan clutch?
     
    Last edited: Apr 24, 2022
    spsauerland Thanks this.
  4. baha

    baha Road Train Member

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    Try and unplug the power wire connector at the valve you will find at the end of air line coming from the fan, crank it up, see fan runs and if it does you may need to replace the air controll valve with the one that free wheels with air going to it and turns with no air goingto the fan?
     
  5. spsauerland

    spsauerland Road Train Member

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    98 could be air applied fan clutch, not air release.
     
    bjytech Thanks this.
  6. irishluck09

    irishluck09 Light Load Member

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    Alright so I took a little diagnosing. Like you said, disconnected the plug from air solenoid and turned on truck, fan is not engaged. Still free spins. I decided to check for air at the solenoid. There IS air coming into it. But I dont want to replace it not knowing if it's an applied air clutch or not. Im going to assume that it requires air to engage it hence looking at the fan clutch there is a gap between the 2 plates.
     

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  7. irishluck09

    irishluck09 Light Load Member

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    So possibly a bad air solenoid? (And yes I took the air line off). The fan worked 3 weeks ago when I bought it testing it with the manual fan switch(which does not work either turning the fan on)
     

    Attached Files:

  8. irishluck09

    irishluck09 Light Load Member

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  9. spsauerland

    spsauerland Road Train Member

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    It is a Horton HT fan clutch, air to engage fan clutch. Solenoid can be plumbed N.O. or N.C. Have to bench tested fan clutch actuator?
     
  10. irishluck09

    irishluck09 Light Load Member

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    Okay so my air valve is a normally close valve. I checked the valve and it's working. And I do have air coming in. So I guess at this piont I need to chase the ground and power to the ecm while checking for breaks.
     
  11. spsauerland

    spsauerland Road Train Member

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