Mark Viii Fan Wiring Issues

Discussion in 'Fox 5.0 Mustang Tech' started by elarm1, Sep 7, 2013.

  1. image.jpeg
    I have my Mark VIII fan with Derale 16749 controller and a Bosch 75 amp relay and new Canton overflow bottle. Anyone have and DETAILED wiring diagrams so I can get my ride running again? Everything else is done but the wiring. Please help!
  2. Careful with that controller. It could have just been me, but mine gave out and the car overheated. I finally put a thermometer in the radiator, and adjusting the potentiometer made no difference. It would randomly turn on and off. Usually once the car was already at 215.
  3. anyone with detailed instructions??? Thanks gear banger but that was pretty much common sense
  4. It's time you learned how to use Google - this came up in less that 10 seconds using derale 16749 instructions as the search title - It even has pictures....

    Alternate placement for a temp gauge sender:

    Revised 24 July 2011 to add better temp sender location description and the necessity to loop the fluid flow through the heater circuit.

    How it works:
    If you want any kind of operation similar to stock, the ECT/heater feed line is the best place for a temp sender or fan thermo sensor. After all, the computer uses the ECT to pick up data on how warm the engine is. Putting the temp sender in the same line as the ECT is a simple way to get the best possible accuracy at minimum cost and complication.

    Some things to keep in mind:
    Just be sure that you haven’t blocked the coolant return because of a leaky heater core. For this to work correctly, the coolant needs to flow from the ECT sensor tubing back to the water pump. That means a leaky heater circuit gets looped rather than just plugged up. Join the rubber hoses together with a hose splice from Home Depot rather than plug them up.

    Where to put it:
    Use the heater feed that comes off the intake manifold that has the ECT sensor in it. Cut the rubber hose that connects the manifold water feed to the heater and splice in a tee adapter for the temp gauge sender. That way you will get the most accurate temp readings since the coolant is always flowing through the heater circuit in a stock car.

    Tee adapter info:
    Make a pilgrimage to your local hardware or home supply center and get some copper pipe and a tee that fits the temp gauge sender. Solder two pieces of copper pipe onto a copper pipe tee with threads in the tee part. Find the correct brass fitting to match the temp sender threads to the tee fitting.


    DYI answer to electric fan problems...

    If you are good with electrical stuff (90% of the people here aren't), build your own controller. The numbers on the diagram (#86, #87, etc) refer to the numbers on the bottom of a typical automotive relay.


    Note that the temp sensor in the diagram needs to match the thermostat in your engine. The preferred arrangement is to have it open about 5 degrees above the thermostat.

    To allow the ignition switch to control the fan so that it does not run when the ignition is off, connect the relay contact #86 to the red/green wire on the ignition coil or to the red/yellow wire on the coolant level sensor.
    #5 jrichker, Sep 7, 2013
    Last edited: Sep 7, 2013
  5. I understand how to use google. Maybe you ALL did not understand my question... I put pictures in place to show what I have done. I asked for DETAILED instructions on how to wire me Derale controller to my Bosche relay to my car. If you do not have those DETAILED instructions that is ok. Just do not use silly statements like "It's time you learned how to use Google". Anyone have DETAILED instructions on how to do this?
  6. I'll sell you my harness. $5 bucks. Controller is shot, but you could just plug in yours.
    I used the Derale 25 amp relay to switch a higher amp relay. Its got a 50 or 60 amp, but yours will plug in too.

    Hooks to the ac clutch, starter solenoid, chassis ground, temp sensor, fan and ignition accessory.

  7. Thank you for the update. I think I will step aside and let other people help you. It seems that there is a gap in your understanding how electrical stuff like relays work and a gap in my understanding of what you wanted to do. Maybe one of the other 5 or 6 people in 5.0. Fox Tech who really understand automotive electrical circuits will step up and fill in your gap... If that doesn't happen, you are going to have fun learning how electrical circuits work...
  8. View attachment 124929
    Ross12 likes this.
  9. That is fine and dandy. I enjoy learning. But like most Americans, I'd rather find an easier way out. Since my google doesnt work, i'll break out the britannica. Thanks for your help.
  10. JR is one of the original wise-men here and he's only trying to help (as he's helped zillions of people before). Conduct like this will probably not yield a lot of folks jumping in to assist.

    Providing a benefit of the doubt, let's shift the question back to you instead of us trying to guess. The instructions that JR linked to are pretty explicit. With those as a reference (so we're all on the same page), please tell us what aspects (specifically) of the instructions (or the application of those instructions to your circumstance) you are having difficulty with.
    larrym1961 likes this.
  11. Didn't it come with instructions about what color wires go where? I thought mine did.

    You're making it harder on yourself by adding the larger relay into the circuit.


    If you make the pic full size you should see the wires. The large red wire out of the derale controller gives a ground to the larger relay. The hot side is fed from ignition accessory wire - the small red wire that goes to the yellow wires. The contacts in the second relay close the ground to the fan. The hot side of the fan is the large red wire with the ring terminal and it connects to the starter solenoid. The green and black wires with the spade connectors are the chassis grounds. The green wire that is spliced into the grey I had to the hot wire of the ac clutch.

    I still sell you mine. Might be easier. You're going to have to tape it back up though.

  12. I concur, and I will leave it at that... For now.

    Awesome seeing you around Hissin. :)
  13. I am good now, and I made my harness from an enlarged pic of what you had Jeaded. Thank you. I am not the smartest nor do I claim to be the smartest and all I wanted was some pictures. I never asked for smart comments but I guess it's just better to be smarter than everyone else in a place where comments like these are accepted. Its not accepted by me and I do not appreciate it. Thanks all for your help.
  14. Dude, you have a bad attitude. At worst, jrichker was being a little tongue and cheek with you. He also provided the most detailed response of this thread. If this is how you "appreciate" the help people give you, count on having to solve most of your upcoming issues yourself. A little humility goes a long way....the piss poor attitude doesn't!
    larrym1961 likes this.
  15. I have a bad attitude for asking for help?
  16. Rewind.... I ask for help, I get a little and ask for more, I get cheek and mouth action and not in a good way and I have a bad attitude?
  17. I think he is just trying to tell you that there is no need to jump on people when you are asking for help. If you feel offended by an individuals comment, maybe a PM would be better to clarify any conflicts. All I saw were people trying to help, even after you got uppity. Take the advice with a grain of salt. I mean, if i offered solid advice to someone and they flipped on me I most likely would not want to help them again. At least you got your car working, there is good news at least.
  18. Whats the black box that's wired at the top of the fan in the pic?

  19. Word of advice in life in general. When asking for help, two words come to mind that go a long way


    Joe has helped thousands of folk, including me over the years. I bet Joe has answered the same questions 1000 times without charging a penny

    Recently, I had a situation that was stumping me with my car. Joe offered help and quite frankly I could have taken one of his responses as being condescending or rude, but you know what? I said nothing because I asked for help and that's all that matters. We are all big boys and girls. If you don't want to hear what someone says, don't expect them to help you in the future. Getting snippy in the public forum isn't going to motivate others to offer help either. A private PM would have been a better solution.

    By the way, I ended up solving my issue myself but still appreciated all the input. Even the rude ones...:rolleyes:

    just my .02

    Glad you got it figured out.