Removing the blower motor switch

Discussion in 'Ranchero Tech Help' started by Make, Oct 20, 2020.

  1. Make

    Make In First Gear

    Messages:
    23
    I should check the -79 Ranchero blower motor switch and possibly replace it, but I don't understand how to get it off.

    Is it screwed into that Vacuum Damper Door Switch?

    The switch is probably original.
     
  2. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    11,175
    Location:
    Seguin, TX
    I have a spare A/C control panel, I'll take a pic or two, post them up, so you can see how the switch is attached.
     
  3. Make

    Make In First Gear

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    23
    It would be great !
     
  4. 1978GT

    1978GT In Fourth Gear GOLD MEMBER

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    310
    Before replacing the blower switch, explain the problem(s) with the blower: no power, one speed only, etc. The solution could be a fuse or breaker, or more likely the blower motor resistor.
     
  5. Make

    Make In First Gear

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    23
    I try Google Translate, my native language is not English, wait a moment, or an hour.
     
  6. Make

    Make In First Gear

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    23
    The last time the car was driven, it might not have worked other than the maximum speed of the fan motor.

    I measured the resistances of the fan motor resistors and those values were at least logical, I don’t know how much they should be exactly, but the fault is hardly there.

    I have the fan wire disconnected from the fuse board and those four wires disconnected from the fan motor resistors and when I measured the resistances of the wires in between, the blue wire would seem to be OK, but there was clearly too much resistance in the other wires.

    That is, the fault is a blower motor switch, or between the switch and the resistors in the wires, I still don't know which one, when I can't even get that wire connector off that switch, it's in such a cramped place.

    It would make it easier when I got that blower motor switch in my hand.
     
  7. thebruins

    thebruins In Third Gear

    Messages:
    108
    It's just one screw that attaches the blower motor switch to the control unit. May have to take the entire unit out or loosen it and push it back to get to that screw.

    If only max speed is working and the blower motor resistor is ok, that would mean something is wrong between the switch and the resistor. I have the wiring diagram somewhere if you need it.
     
    Make likes this.
  8. Make

    Make In First Gear

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    23
    I removed those four screws from that control unit today, but it's a very small movement what that control unit moves with that two electrical connectors attached, air hoses, some wire.

    I can't get that control unit out of there, impossible.

    So it's stuck with one screw ... I should know where that screw is. handy_andy_cv64 promised to inject a couple of pictures of how that switch is attached to that control unit.

    Thanks, but I have some sort of wiring diagram for that.
     
  9. LSChero

    LSChero In Maximum Overdrive PLATINUM MEMBER

    Messages:
    2,264
    Location:
    Area 6 NV
    I had to gut the cluster and ducts to get at fan and control switches.Re-check amp draw from resistor to fan,here are specs for 74.
    SAM_4643.JPG SAM_4641.JPG SAM_4447.JPG
     
    Make likes this.
  10. Make

    Make In First Gear

    Messages:
    23
    Yes, I also have the instrument panel removed, but I wouldn't bother to remove the air ducts.

    That wiring is clear to me.
     
  11. thebruins

    thebruins In Third Gear

    Messages:
    108
    I pulled my control unit 3 years ago by simply disconnecting the 2 vacuum connectors, 2 electrical connectors and the temperature cable. After that I simply wiggled it out of there and had it in my hands. Curious why you guys had/have a much harder time.
     
  12. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    11,175
    Location:
    Seguin, TX
    I haven't yet found my extra panel, I thought it was in my truck. Hopefully it's not in storage, because the owners haven't removed their lock after catching up the payments.
     
  13. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    11,175
    Location:
    Seguin, TX
    Hah, I can be downright stupid sometimes! It wasn't in the S#!tbox, it was in Babe, behind the passenger side of the seat! Along with a few other items I was looking for...

    ...pics in a few minutes!
     
  14. Make

    Make In First Gear

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    23
    Great, I have tried the Internet to search for images or videos where the switch and Vacuum Damper Door Switch are together but I have not found.
     
  15. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    11,175
    Location:
    Seguin, TX
    Here's the panel with the switch in place. Of course, you need to remove the buttons on the levers to make removing the panel easier.
    PSX_20201021_130610.jpg

    This pic shows the one screw holding the switch and bracket in place. The panel could be moved into a position to remove that screw, if you remove the vent above the panel first.
    PSX_20201021_130634.jpg
    And, make sure the contact pins are clean, and the terminals they slide into are clean and tight.
    PSX_20201021_130659.jpg
     
    Make likes this.
  16. Make

    Make In First Gear

    Messages:
    23
    Many thanks for the pictures.

    I'm not sure if my car has that kind of combination.

    That electrical connector above that blower motor switch connector is, I remember, vertical, you have it horizontal, so I mean the connector in that Vacuum Damper Door Switch.

    That blower motor switch is different from what Rockauto.com sells for the 1979 Ranchero
     
  17. thebruins

    thebruins In Third Gear

    Messages:
    108
    I guess Rockauto has the wrong switch listed. As you mention, the flat side of the switch’s lever and the flat side of the mounting tab should be on the same plane on the switch. Part number is D5OZ-19986-B. My '79 car has it and just like Andy my extra unit has it as well.
     
    Last edited: Oct 21, 2020
  18. Make

    Make In First Gear

    Messages:
    23
    That's what it looks like.

    Now that I know how I should get that switch out of there control panel, then maybe ... I'll get that electrical connector out of that switch too, so I can get it tested.

    If the fault is in the switch, then I worry about where to get the right kind of switch.

    So I really don’t have so much force on my fingers that I could get that electrical connector out of that switch when that switch is attached to that control panel.
     
  19. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    11,175
    Location:
    Seguin, TX
    You disconnect Ford electrical connectors with a small flat-blade screwdriver, or a pick tool. Lift the locking tab, or tabs, just enough to start pulling the connector out, rocking it back and forth as you pull.
     
    Make likes this.
  20. Make

    Make In First Gear

    Messages:
    23
    I have to try, usually it does so with those old connectors that they break.
     

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