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  •  » Heater motor wiring ... 2 wire vs 3 wire . No resister in box

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    7/12/2020 4:05 PM  #1

    Gaba
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    From: Van Alstyne Texas
    Registered: 1/15/2014
    Posts: 1,009

    Heater motor wiring ... 2 wire vs 3 wire . No resister in box

    I had an original 65 heater box that had no resistor box on it .. and the motor seemed to have two pig tails going to harness and one ground getting screwed in on the firewall

    Now , I didn’t know things would have been so different with another used rebuilt box I got from a 65-66, and I swapped out the heater box and core and motor.. noticed  the heater box had a resistor on it with broken terminal (I thought no issues )  , and the motor was new two wire .. I hooked it all up , no go.. tried to switch around the wires on the motor to the wires coming from harness , and nothing .

    I tried a 12 v battery straight to the motor and it turns perfectly fine ...

    No idea what to do now .. how to wire this up to work?

    How different is a 2 wire fan setup from a 3 wire?

    What’s easier ::: adapt this to work? Or get a 3 wire fan motor and re-reinstall the heater box?

    Last edited by Gaba (7/12/2020 4:07 PM)

    If it aint broke, I have'nt tried to "Fix" it yet!
     

    7/12/2020 4:54 PM  #2

    50vert
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    From: QLD Australia
    Registered: 4/01/2013
    Posts: 1,427

    Re: Heater motor wiring ... 2 wire vs 3 wire . No resister in box

    Put your original 3 wire motor into the resistor case.
    If it died,
    https://www.npdlink.com/product/blower-motor-heater-repro-motor-only-with-correct/195675?backurl=search%2Fproducts%3Fsearch_terms%3Dblower%252Bmotor%26top_parent%3D200001%26year%3D1965&year=1965
    It's what I plan on doing in the same situation.

    "Those telephone poles were like a picket fence"
     

    7/12/2020 5:25 PM  #3

    wsinsle
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    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,703

    Re: Heater motor wiring ... 2 wire vs 3 wire . No resister in box

    If you want to use the 3 speed set up, you need a a 3 speed switch on your dash. You need the 3 speed harness from the switch to the  resister pack and to the motor. If you have a 2 speed switch on your dash I would get another 2 speed motor. 

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

    7/12/2020 6:42 PM  #4

    terry
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    From: vandalia, illinois
    Registered: 4/01/2013
    Posts: 1,871

    Re: Heater motor wiring ... 2 wire vs 3 wire . No resister in box

    Gaba, the difference is the  early 65s had 3 wires to the heater motor and the later 65 only had 2.  When I bought my october 64 built fastback I could only get 1 speed to work.  At some point in time the fan had been exchanged for the wrong one.  While searching for the answer to this problem I discovered the difference in the 2.  I also discovered several wires on my 65 did not match the wiring diagram for a 65.  I bought a wiring diagram for a 64.5 and BAAAM it was on the money!!  If you look at this page from Johns mustang it shows 2 motors for the 65.  Before 4/1/65 and after https://johnsmustang.com/collections/1964-1973/a-c-&-heating?filters%5Bcategory3%5D%5B0%5D%5B0%5D=Heater%20Motor%20Assembly

     

    7/12/2020 7:02 PM  #5

    Texas!
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    Registered: 6/27/2014
    Posts: 232

    Re: Heater motor wiring ... 2 wire vs 3 wire . No resister in box

    On the cars WITH the resistor, it is in the GROUND circuit. The blower motor is fed 12V POWER any time the key is in the ACC or ON position.

    Last edited by Texas! (7/12/2020 7:03 PM)

     

     

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  •  »  Heater motor wiring ... 2 wire vs 3 wire . No resister in box

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