Results 1 to 6 of 6

Thread: For Those With Electric Cooling Fans - Piggy Back Sending Unit?

  1. #1
    Registered User Hardway's Avatar
    Member ID
    CZCC-26208
    Join Date
    Jan 2012
    Location
    Austin TX
    Posts
    659

    Default For Those With Electric Cooling Fans - Piggy Back Sending Unit?

    I have gone back to the stock style mechanical clutched fan on my 240z for now along with a MSA shroud that is on the way. My car had dual 10 or 12 inch cooling fans on it but the temp probe for the wiring kit would have required bending up some of the fins on my brand new Champion radiator and I did not want do that. I am wondering, can you use the original sending unit that is near the thermostat housing to also trigger a set of electric fans? Basically having 2 wires on it instead of the just 1 wire for the gauge in the dash? I have seen more advanced wiring kits that include a screw in temp sending unit but as of right now by engine only has the single sending unit for the dash gauge. I am asking because if I want to go back to electric fans I will know what is ahead of me. Thank you.
    08/1970 240z Series-1 #8011 - Silver, black int., 2.4L I-6, 5spd, 90% restored.
    06/1973 VW Karmann Ghia - Black convertible, 4spd, 1600cc air-cooled engine.
    11/2013 Scion FR-S - Silver, 6spd, a car with the soul of a Z for the modern times.
    Restoration thread of my old '72 240z -> http://www.classiczcars.com/forums/o...1972-240z.html

  2. #2
    No more body roll! SteveJ's Avatar
    Member ID
    CZCC-5413
    Join Date
    Dec 2003
    Location
    Gainesville, GA
    Age
    54
    Posts
    3,651

    Default

    Not easily. The sending unit changes resistance according to temperature. The thermostat for the fans is more of an on/off switch. If you did manage to find a way, it would probably adversely affect the reading on the temperature gauge.
    73 240Z
    74 260Z

    Blue's collection of tech tips - A great place to look for answers
    XenonS30 -The cheap source for FSMs
    Georgia Z Club
    Fiddling with Z Cars - Z car tips & tricks and pictures of my car-loving life.
    Steve's CARtography - Just car pictures.

  3. #3
    Registered User Mike W's Avatar
    Member ID
    CZCC-19584
    Join Date
    Jun 2009
    Location
    Austin, TX
    Posts
    243

    Default

    Jeff,

    I had the same issue when I went to electric fans and did not want to mangle my new radiator with either temp probes or the "through the core" tie wraps to hold on the fans.

    My solution to the temp probe turned out to be quite elegant and provided a great deal of programmability in terms of how the fans are actually used.

    I went with a Dakota Digital fan controller which you can find here:

    Electronic Fan Controller 70 Amp

    It is an awesome product that lets you have complete control over fan turn on / off temp, running time after engine shuts off, etc. They also provide a temp sending unit that I ended up installing directly in the block of my Z engine. Turns out there is a fitting/plug (which I believe is there in order to drain the block of water if necessary) on the rear part of the block on the drivers side which I was able to remove and install the sending unit I purchased from Dakota. I recall that I had to find the right thread adapter to make this work, but it was very straight forward. I am not at my home at the moment so I can't get you the thread details, but if you need them I have them at my house. This gets wired directly into the Dakota controller so it will know the exact temp of the coolant within the block. This totally eliminated the need for the probes that go through the core of the radiator. I ended up mounting the controller in my glove box so it is accessible from the inside of the car. Turns out there are a few LED indicators on the controller and being able to see them while in the car can be useful at times.

    This turned out to be a very elegant solution, is completely reversible if desired, and brings some modern technology to an older style cooling system which gives you a lot more control.

    This unit, coupled with the radiator and fan mounting bracket that I purchased from Wizard Cooling along with high performance SPAL fans, has proven to be the most effective cooling system I have seen in a Z yet. I can be sitting in traffic in 100 + degree Austin weather and never go over half way on my temp gauge. In fact when the fans kick in (they sound like turbines by the way) you can actually watch the temp go down even while standing still. My old system never performed quite like this.

    Hope this helps. I'd be happy to show you what I've done if you ever decide to go back to the electric setup.

    Mike.

  4. #4
    Registered User Hardway's Avatar
    Member ID
    CZCC-26208
    Join Date
    Jan 2012
    Location
    Austin TX
    Posts
    659

    Default

    That is awesome Mike! Your Z truly gets the best of everything. I will look in to the Dakota module should I need to go that route. Knowing there is another temp sending unit location is the best piece of knowledge to have. Thank you for your detailed post.
    08/1970 240z Series-1 #8011 - Silver, black int., 2.4L I-6, 5spd, 90% restored.
    06/1973 VW Karmann Ghia - Black convertible, 4spd, 1600cc air-cooled engine.
    11/2013 Scion FR-S - Silver, 6spd, a car with the soul of a Z for the modern times.
    Restoration thread of my old '72 240z -> http://www.classiczcars.com/forums/o...1972-240z.html

  5. #5
    Registered User Walter Moore's Avatar
    Member ID
    CZCC-3035
    Join Date
    Oct 2002
    Location
    Indianapolis
    Posts
    1,833

    Default

    I mounted a temperature switch in the heater line for the SUs. You have to buy a BSPT to NPT adapter nipple, and a T for the switch.Click image for larger version. 

Name:	Temp_Switch.jpg 
Views:	20 
Size:	168.4 KB 
ID:	72633

    But it seems to work well. I know that I bought the temperature switch from Summit Racing, but it was 3 years ago and I don't remember the part number.
    '71 240Z, Because any fool can drive fast in a straight line.

  6. #6
    Registered User
    Member ID
    CZCC-28905
    Join Date
    Jan 2013
    Location
    New Lenox, Il
    Age
    55
    Posts
    10

    Default

    This is the controller I used and am very happy with. Straight forward installation.

    HPC Electronic Radiator Fan Controller Control Module with Sensor 102001 | eBay
    1974 260Z 2+2 4/74 build

    Link to Restore Pix: https://plus.google.com/u/0/photos/1...65003972826929

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Cooling fans
    By caltanian in forum Open S30 Z Discussions
    Replies: 12
    Last Post: 12-08-2013, 06:35 PM
  2. 71 fuel sending unit ?
    By timsz in forum Open S30 Z Discussions
    Replies: 3
    Last Post: 11-11-2013, 02:48 PM
  3. oil pressure sending unit.
    By z_ya in forum Help Me !!
    Replies: 2
    Last Post: 11-30-2012, 02:30 PM
  4. Sending unit..
    By guy_geo in forum Help Me !!
    Replies: 3
    Last Post: 08-11-2008, 02:01 PM
  5. Need help for sending unit
    By guy_geo in forum Carburetors (S30)
    Replies: 2
    Last Post: 07-22-2008, 08:59 AM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •