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  •  » Heater/Wiring isue

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    2/26/2015 7:04 PM  #1

    kw120
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    Heater/Wiring isue

    I'm working on a 65 Falcon Sadan Delivery. I'm trying to get the heater working.  I thought the blower motor was out so I bought a new motor but still not working.  When I test the circuit I have 12v to the wires that the blower pluges into.  As soon as I plug the motor in it drops to nothing and the motor will not turn. When I take the motor to the battery is works fine.  Is this a wiring issue? or am I missing something?  This is th same 2 speed blower like the 65 mustangs have.

     

     

    2/26/2015 7:13 PM  #2

    barnett468
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    Re: Heater/Wiring isue

    .
    how many wires does the blower have?

    how many speed positions is on your dash switch?

    is there a small red plate on the ront of the heater box?

    did your old motor ever work?
    .

     

    2/26/2015 7:37 PM  #3

    kw120
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    Re: Heater/Wiring isue

    It is a two speed system,  3 pos switch (off, hi, low) no resistor (red plate) on the box and 3 wires on the motor.  The motor has never worked since I've had the car.

       •Thread Starter
     

    2/26/2015 7:39 PM  #4

    MachTJ
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    From: Wisconsin
    Registered: 5/18/2014
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    Re: Heater/Wiring isue

    Check the ground.

     

    2/26/2015 7:42 PM  #5

    terry
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    From: vandalia, illinois
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    Re: Heater/Wiring isue

    The 65 mustangs used 2 different blower motors depending on when they were built.  Either a 2 wire or a 3 wire.  The early 65s had 3 wires to the blower which I believe were low high and ground.  The later models had 2 wires 1 is hot and the other is ground and they used a resistor to get the lower speed.  using a volt meter see which wire from the switch is hot and which is ground and try to hook it that way to the blower to see if it works.  

    What happened on my 65 is the previous owner replaced a 3 wire blower with a 2 wire and I had to wire it that way or else change motors.  If you look back a week or so I have a thread on this very subject

     

    2/26/2015 7:44 PM  #6

    terry
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    Re: Heater/Wiring isue

    here is that thread

    http://fyi.boardhost.com/viewtopic.php?id=4501

     

    2/26/2015 7:49 PM  #7

    barnett468
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    Re: Heater/Wiring isue

    .
    trace the wiring and check the switch with your tester.

    1965 falcon factory ford wiring diagram

    Interior wiring

    http://www.auto-wiring-diagram.com/2275-wiring-diagrams-of-1965-ford-falcon-6-and-v8-all-models-part-1.html?preview=true
     
    engine compartment.
     
    http://mustangforums.com/forum/classic-mustangs-tech-16/
     

     

    2/26/2015 8:09 PM  #8

    kw120
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    Re: Heater/Wiring isue

    The switch works fine.  I have 12v of power at the harness connections under the hood where the motor attached untill I plug the motor in  As soon as I plug the motor in it drops to nothing.  I hve a good ground.  

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    2/26/2015 8:12 PM  #9

    barnett468
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    Re: Heater/Wiring isue

    kw120 wrote:

    The switch works fine.  I have 12v of power at the harness connections under the hood where the motor attached untill I plug the motor in  As soon as I plug the motor in it drops to nothing.  I hve a good ground.  

    you have a bad connection . . it shows 12v but will not flow enough cirrent . . the switch is bad/dirty/worn or the fuse retaining clips need to be cleaned etc.
    .

    Last edited by barnett468 (2/26/2015 8:14 PM)

     

    2/26/2015 8:46 PM  #10

    Hornman
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    From: Mansfield, Texas
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    Re: Heater/Wiring isue

    The high and low speed wires from the dash switch should have a full 12V at the motor connections when each is selected. The dropping resister is in the motor. Sounds like you may have a bad ground at the motor. Try cleaning the motor grounding points.

    Barnett468 is right about these 50 year old cars being notorious for having heavily oxidized electrical contacts. A glass fiber brush works well to scrub the oxidation from the contacts. A liquid contact cleaner helps too.

    Last edited by Hornman (2/26/2015 8:52 PM)

     

    2/27/2015 6:08 AM  #11

    Bullet Bob
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    Re: Heater/Wiring isue

    And IIRC, the heater motor wires pass through the firewall connector near the center of the f-wall...at least my 66 did when it was nearly stock.  That's another good place for a crappy connection.

    BB

    "you get what you pay for, good work isn't cheap, and there are NO free lunches...PERIOD!"
     

    2/27/2015 7:35 AM  #12

    wsinsle
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    From: Belle Vernon, PA
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    Re: Heater/Wiring isue

    The heater motor wiring for your 65 falcon seems to be the same as 64 mustang.Check terrys link. Because it does not work on either high or low speed my first guess would be the source. Could try checking or changing the fuse. The fuse holder seems to be a problem with these old cars. Try bending the prongs in tighter on the fuse holder.
         You could also make up a jumper with a fuse in it. I like to use a jumper with a fuse, if you short something out you blow the fuse. You don't mealt things. remove the plug from the switch. Jumper from a good positive to the wires going to the fan motor. You should be able to get the fan to run on high and low speed this way. If the motor runs the wiring going out to the fan is good. Problem is from the switch back. If it don't run problem is in wiring going to motor.

     

    If this forum can't fix it, it isn't broke.
     

    2/28/2015 2:34 PM  #13

    MachTJ
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    Re: Heater/Wiring isue

    If you do indeed have 12 volts and a good ground, it still is possible like the last couple posters stated that there may be the green corrosion monster somewhere. The connection may be good enough to show 12 volts and may light up a test light but when you turn on the fan the corrosion can not support the amperage load the fan requires. How does ohms law go again? It takes one amp to push one volt across one ohm of resistance. I think thats the saying. 

     

    3/01/2015 10:11 AM  #14

    BobE
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    Re: Heater/Wiring isue

    I'd first suspect the blower switch as other posts have indicated.  Remove the blower connector, and apply 12v to each blower wire, check for motor operation.  If the motor functions, then re-connect blower switch connector, apply 12v to the source wire to the switch and recheck, if the motor doesn't function, its the switch, if it does, then the problem is the 12v supply to the switch. 
    Cleaning the fuse and the fuse holder can be done w/a regular pencil eraser.  Using abrasives on electrical connections should be avoided, as while it will work, it removes the thin conducting coating and can lead to the problem reoccurring.

    65 Fastback, 351W, 5-speed, 4 wheel discs, 9" rear,  R&C Front End.
     

     

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