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Technical Any reason not to run electric fan 24/7?

Discussion in 'The Hokey Ass Message Board' started by NAES, Mar 11, 2020.

  1. NAES
    Joined: Dec 24, 2008
    Posts: 479

    NAES
    Member

    I only ask because in the last year or so I've killed 3 thermal switches tapped into the intake manifold. These are the $18 dollar ones from Amazon or Ebay and they seem to get mixed reviews at best. I don't know if switching to an AC Delco or similar would do me much better either. I've ended up jerry rigging it a couple of times just to make it home.

    I almost always drive in nice warm 70's to ball meltingly hot weather so the fan is already running after it warms up.

    Of course if the fan dies and stops cooling then thats a separate issue. I've gone through this cooling system multiple times and am currently running the Evaporust cooling descaler with positive results thus far. I'll drain it this weekend and report back.

    Thanks as always for the great input guys. NAES

    Sent from my SM-N950U using The H.A.M.B. mobile app
     
  2. Inked Monkey
    Joined: Apr 19, 2011
    Posts: 1,823

    Inked Monkey
    Member

    I have a thermal switch on the ones in my 52 but I also have a toggle switch for direct power. I always end up just turning the fan on when I need it.
     
  3. 325w
    Joined: Feb 18, 2008
    Posts: 5,375

    325w
    ALLIANCE MEMBER
    from texas

    Is the fan ground good?
     
  4. Sounds like a ground or inadequate wire size. But as you suggest it may be inferior switches.
    I have a ground wire bolted to engine so I can pull wire off a failed switch to run fan continuously to get me home. But I think running the fan whenever the engine is running will cause my high quality fan to fail prematurely.

    Phil
     
    town sedan, Fordor Ron and jim snow like this.

  5. yea the motor burns out.
     
  6. 49ratfink
    Joined: Feb 8, 2004
    Posts: 17,852

    49ratfink
    Member
    from California

    24/7 ?? that would kill the battery.:confused:
     
  7. What temperature range is your engine inhabiting?
     
  8. What’s the amperage rating on the switch ?
    Are you running a relay?

    wire it like the factory did with factory parts and you’re probably going to be ok.
     
    verno30, sunbeam, trollst and 5 others like this.
  9. Run a hight current relay mate and it will save the switch from carrying the load of the fan

    Sent from my SM-G960F using Tapatalk
     
    verno30, town sedan, Roothawg and 8 others like this.
  10. Bingo! ....Use a relay -fans pull a lot of juice
     
  11. Blue One
    Joined: Feb 6, 2010
    Posts: 10,678

    Blue One
    ALLIANCE MEMBER
    from Alberta

    Anything wrong?
    You mean besides the fact that they sound like a Hoover vacuum cleaner?

    I initially thought that I had no choice but to use one on my RPU.
    I had it installed and on test running the fan I decided it had to go.

    I worked hard to get a mechanical fan installed.

    There wasn’t much room and issues to address with my steering tie rod but after trying 2 different mechanical fans in the end I made it work.

    I’m much happier with my choice because now I don’t have to listen to the stupid thing run and I also didn’t have to wire it or deal with any problems like you have now.

    You should probably check with the manufacturer of the electric fan to see if the motor is rated for continuous running or not.
     
    Last edited: Mar 11, 2020
  12. NAES
    Joined: Dec 24, 2008
    Posts: 479

    NAES
    Member

    Wow thanks for the super quick replies everyone!

    Here's some followup info. Thermal switch runs to a relay. Hot is off the + terminal of the battery. Negative runs to a body ground (engine has ground strap to frame). Relay activation comes from a spare ignition hot from the fuse panel (Rebel Wiring Harness). Wires are all larger than the fan wires so I assumed I was good there.

    Pics aren't loading. I assume I need to mess with the permission settings on my new phone so I'll try and fix that.


    Sent from my SM-N950U using The H.A.M.B. mobile app
     
  13. NAES
    Joined: Dec 24, 2008
    Posts: 479

    NAES
    Member

    I didn't think I needed to clarify 24/7 as meaning while the engine is running but for you I'll make sure to be extra clear. For crystal clear clarity, 24/7 while the engine is running, my bad.

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  14. NAES
    Joined: Dec 24, 2008
    Posts: 479

    NAES
    Member

  15. 4wd1936
    Joined: Mar 16, 2009
    Posts: 851

    4wd1936
    Member
    from NY

    That pipe tape on your switch may be the culprit, if there is not a good ground/increased resistance that could be smoking the switch. I use dielectric grease to seal the threads and it usually works well. You could also run a good ground to the body of the switch.
     
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  16. 24 hours a day 7 days a week
    Not a substitute for anything else.

    try it -
    Can I run my fan 24 hours a day 7 days a week while my engine is running. Besides it not making any sense as well as contradicting it’s begging for a smart ass comment


    I use either BWD or Standard products switch and can’t recall any repeating failures
     
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  17. 2935ford
    Joined: Jan 6, 2006
    Posts: 3,410

    2935ford
    Member

    Yup, that's my method.
     
  18. 325w
    Joined: Feb 18, 2008
    Posts: 5,375

    325w
    ALLIANCE MEMBER
    from texas

    Ad a star washer at the ground bolt. Might not fix it but can't hurt it.
     
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  19. Penetrator
    Joined: Aug 25, 2011
    Posts: 438

    Penetrator
    Member
    from SK CAN

    What the hell is this?

    [​IMG]

    .
     
  20. See post 15 by 4wd1936 above.

    Phil
     
  21. Neb Hillbilly
    Joined: Dec 20, 2019
    Posts: 337

    Neb Hillbilly
    Member

    I never use them, but when I do I use the Chrysler mini van switch to control them

    Sent from my S48c using The H.A.M.B. mobile app
     
    Lil'Alb likes this.
  22. Good idea Ned. Do you happen to have a number?

    Also note when using Standard Auto Parts there is a difference between a temperature sender switch (TS) and a fan switch (FS) preceding part number. They do look alike.

    Phil
     
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  23. triumph 1
    Joined: Feb 9, 2011
    Posts: 476

    triumph 1
    Member

    I would start by cleaning your positive battery terminal as it looks a little corroded in the pic. & definitely clean the ground adding a star washer.


    Sent from my iPhone using H.A.M.B.
     
    town sedan likes this.
  24. gene-koning
    Joined: Oct 28, 2016
    Posts: 2,027

    gene-koning
    Member

    My 1st hot rod I put a used electric fan and I ran the wiring through the ignition switch. When ever the motor was running, the fan was running. I put 66,000 miles on that original used electric fan without an issue. The fan was out of a Chrysler mini van, and the van the fan was on probably had 100,000 mile on it before it went into my car.
    I don't think I would have the same unconditional trust with an aftermarket electric fan, the mini van fan was an oem fan with a Mopar part number on it.
    Also, I agree with the sealant on the switch threads, things like this are supposed to be screwed right into the intake or head without and form of sealant on them. Gene
     
    Bondo Slinger likes this.
  25. The only way I have ever been able to make them work is to catch the power from the starter and run them through a relay using a simple on/off switch. I use a 40 amp relay and toggle switch from NAPA. The relays and switches off the shelf at Autozone and the like are junk.

    With the heat down here the fan just runs constantly anyway regardless of how it’s wired up.
     
  26. 1oldtimer
    Joined: Aug 21, 2003
    Posts: 7,600

    1oldtimer
    ALLIANCE MEMBER

  27. nochop
    Joined: Nov 13, 2005
    Posts: 1,730

    nochop
    Member
    from norcal

    Scuff up too
     
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  28. NAES
    Joined: Dec 24, 2008
    Posts: 479

    NAES
    Member

    No feathers ruffled but its way more Ghey to be stuck on the side of the road overheating. I used the mechanical fan and OG radiator for several years but constantly fought high running temps.

    Sent from my SM-N950U using The H.A.M.B. mobile app
     
  29. NAES
    Joined: Dec 24, 2008
    Posts: 479

    NAES
    Member

    Connector off of the electric fan. No connector provided.

    Sent from my SM-N950U using The H.A.M.B. mobile app
     
  30. NAES
    Joined: Dec 24, 2008
    Posts: 479

    NAES
    Member

    Thanks everyone for the replies. I'll be making a parts run tomorrow and will use all the suggestions I can and plan on wiring in a backup switch

    NAES

    Sent from my SM-N950U using The H.A.M.B. mobile app
     

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