Forum Discussion

hughesjm21's avatar
hughesjm21
Explorer
Feb 19, 2020

Cummins 6.7 ISB no power to fan clutch

While checking under the coach for filter numbers, I noted an electrical connector that was hung up on water pump pulley (I think). The belt had chewed through the wires that went to the connector. I think this may be the pigtail that goes to the fan clutch for radiator fan. Access is very limited in the area. I have no idea how long this condition had existed.

My question is how does the fan clutch fail when there is no power to it? Is it engaged or not?

9 Replies

  • Cummins12V98's avatar
    Cummins12V98
    Explorer III
    Feb 19, 2020
    "2013 Tuscany 40EX 360 Cummins, Allison 3000, Freightliner" This is what the OP is referring to.

    He did mention "coach" but that is really the only info besides it being a "Cummins 6.7 ISB no power to fan clutch" as mentioned in the thread title.

    This is what I mentioned checking with a CUMMINS Dealer and NOT a RAM/Dodge Dealer.

    When posting questions give as much info as you can, you will get better answers!
  • Ductape's avatar
    Ductape
    Explorer
    Feb 19, 2020
    hughesjm21 wrote:
    None of the above answers provided answer the question. They are only opinions with no useful information.


    That’s your opinion. Perhaps you have a lack of comprehension. You’re not even certain what wires you’re talking about or where they terminated. I don’t give a rats rump what your issue is or anything further you care to comment on.
  • Bipeflier's avatar
    Bipeflier
    Explorer
    Feb 19, 2020
    Using commons sense here, I would assume the engineers made the fan "fail safe" in that if it loses power it runs all the time. The electrical signal from the temperature sensor/ECM will turn it off if the cooling is not needed.

    You could ask the Dodge guys at the garage to confirm but my guess is that it runs all the time with the wires cut.
  • Cummins12V98's avatar
    Cummins12V98
    Explorer III
    Feb 19, 2020
    hughesjm21 wrote:
    None of the above answers provided answer the question. They are only opinions with no useful information.


    You ONLY have gotten what you have paid for!

    If you don't want to deal with it your self take it to a Cummins Dealer and get it fixed.

    More "FREE" advice. :B
  • hughesjm21's avatar
    hughesjm21
    Explorer
    Feb 19, 2020
    None of the above answers provided answer the question. They are only opinions with no useful information.
  • Ductape's avatar
    Ductape
    Explorer
    Feb 19, 2020
    I’m surprised you don’t have a check engine light on. The fan clutch is PWM variable speed, and I’d think the ECM would be monitoring the clutch and it’s response.
  • Johno02's avatar
    Johno02
    Explorer
    Feb 19, 2020
    If you have driven it with the wire broken, it is probably not engaged with power off. If it is engaged, the roar and drag is very apparent. My non-electric fan clutch locked, and about 10 MPH was top speed.
  • ScottG's avatar
    ScottG
    Nomad
    Feb 19, 2020
    You need to replace it with same. Don't skimp or take short cuts or it will get even at the worst of times.

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