Bypass switch for AC clutch fan

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by CDL CPL, May 6, 2018.

  1. CDL CPL

    CDL CPL Light Load Member

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    I am trying to rig up a bypass switch for my AC clutch fan. Where is the electrical switch or what wires would I need to tap into to make said bypass? The clutch fan wont kick on and it's way to hot. I can fix when I get home this is just temporary. Any help is much appreciated.
     
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  3. ClineER

    ClineER Light Load Member

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    Depending on truck, usually if you unplug high pressure switch for fan solenoid the fan will stay lock in.
     
  4. CDL CPL

    CDL CPL Light Load Member

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    Iowa
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    Its a DD15 2013 freightliner cacadia. The fan is locked in place when the ignition is turned over to the accessories . When i crank her on and the psi builds up, it free spins. I watched a guy on youtube stop his fan by hand while the truck is running and fan was engaged. He was able to spin freely as if the clutch wasnt engaged. I did the same thing. Lol i know right....i was able to spin the fan freely as if wasnt engaged.. any way i could by pass and maually switch it on/off? Second question by installing manual switch would it make my AC run again?
     
    Last edited: May 6, 2018
  5. GrapeApe

    GrapeApe Road Train Member

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    If all you want to do is make your engine fan run all the time until you can get it fixed, just unplug the electrical connector on the fan solenoid.
     
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  6. CDL CPL

    CDL CPL Light Load Member

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    Realy thats it? Unplugin both those things wil keep it running? Could this be why my AC isnt working? From what i read, a bad AC will affect the temps on the engine. You wouldnt happen to know how i could go bout checking the AC system . With out having to spend so $$ at Loves or Sapps. Or maybe troubleshoot a few things to narrow it down a bit. Would realy apreciate it
     
  7. Dave_in_AZ

    Dave_in_AZ Road Train Member

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    If the compressor locked up, and went Vesuvius into your system, you basically need a new system.

    Go buy a shop and have it checked, in the event it hasn't yet.
     
  8. GrapeApe

    GrapeApe Road Train Member

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    What are "both those things" that you're talking about? You only have to unplug the fan solenoid to make the fan run, you don't need to touch the A/C switches.
     
  9. CDL CPL

    CDL CPL Light Load Member

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    Im not sure if its accurate or not, I read somewhere if u turn over the key to the accessories [to the right] the fan should spin freely. But if u cant spin then its seized up
     
    Last edited: May 6, 2018
  10. CDL CPL

    CDL CPL Light Load Member

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    Im sorry i miss read the first post.
     
  11. Dave_in_AZ

    Dave_in_AZ Road Train Member

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    That is mostly correct.
     
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