FYI FORD - MustangSteve's Ford Mustang Forum
The Internet's Most Knowledgeable Classic Mustang Information
IF YOU HAVE A QUESTION ABOUT CLASSIC FORD MUSTANGS, YOU HAVE COME TO THE RIGHT PLACE!
MustangSteve has over 30 years of Mustang experience, having owned 30 of them and restored several others. With the help of other Mustangers, this site is dedicated to helping anyone wanting to restore or modify their Mustang.... THERE ARE NO DUMB QUESTIONS!!!!!
Visit MustangSteve's web site to view some of my work and find details for:
FYIFORD Contributors' PICTURES - Power Brake Retrofit Kits for 65-66 Stangs - Classic Mustang FAQ's by MustangSteve - How to wire in a Duraspark Ignition - Mustang Ride Height Pictures and Descriptions - Steel Bushings to fit Granada Spindles to Mustang Tie Rods - Visit my EBAY store MustangSteve Performance - How to Install Granada Disc Brakes MustangSteve's Disc Brake Swap Page - FYIFORD Acronyms for guide to all the acronyms used on this page - FYIFORD Important information and upcoming events

You are not logged in. Would you like to login or register?

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  » ignition switch question

    • 1 of 1

       

    7/09/2018 3:13 PM  #1

    retired 65
    I FYI 24-7

    Offline

    From: nixa, mo.
    Registered: 4/02/2013
    Posts: 336

    ignition switch question

    I replaced my ign. switch on my '65 and on the replacement switch, there is an extra blade terminal on the side and end of the new switch.  It is outside of the pigtail that plugs onto the end of the switch assy.  Does anyone know what that terminal is used for?  Thanks  Jerry

    Last edited by retired 65 (7/10/2018 2:15 PM)

    "when I drop something, it always goes to center of the car"
     

    7/11/2018 12:54 PM  #2

    retired 65
    I FYI 24-7

    Offline

    From: nixa, mo.
    Registered: 4/02/2013
    Posts: 336

    Re: ignition switch question

    retired 65 wrote:

    I replaced my ign. switch on my '65 and on the replacement switch, there is an extra blade terminal on the side and end of the new switch.  It is outside of the pigtail that plugs onto the end of the switch assy.  Does anyone know what that terminal is used for?  Thanks  Jerry

    any help on this?
     

    "when I drop something, it always goes to center of the car"
       •Thread Starter
     

    7/11/2018 1:33 PM  #3

    coachJack
    Active Member

    Offline

    Registered: 5/23/2017
    Posts: 7

    Re: ignition switch question

    Jerry,

    On my 67 Cougar, the extra blades on the side of the ignition switch are "prove out circuits" which provides a ground for the brake warning light when the ignition is turned to the Start mode. 

    Proof Circuit - Switch Position between ON and START. At a point past the ON position and before the Start position there is continuity between the proof terminal and ground P and G (via the switch body). This continuity between P and G continuity is maintained through the START position and no continuity when returned to the Run position.  

     Coach Jack

     

    7/12/2018 5:55 PM  #4

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,711

    Re: ignition switch question

    First of all sorry for the slow response. I've been away from this for a while and have put my books and notes away somewhere and couldn't find them. I searched the internet for info on this and got conflicting info. One pic I found said that is for battery positive, that's not  right. One pic I found said it supplied positive for brake alarm, that didn't sound right. I finally found my book and notes, nothing on that there. Now you had me hooked, so I tore my whole dash apart to get to the switch. (Not really it's actually not all together) Now I did see pics of a switch with a connector in that position and some pics with just a rivet there. Hmmmm. So I went to my tour apart dash, your fault (just kidding it was never together) and started checking my ignition switch. I did have a tab there for a wire connector, not just a rivet. I measured voltage on, start, acc. and off position. I checked for resistance in all positions. I found nothing, that is used for nothing. I can at least say on my 66 aftermarket ignition switch it is used for NOTHING.

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

    7/12/2018 6:31 PM  #5

    coachJack
    Active Member

    Offline

    Registered: 5/23/2017
    Posts: 7

    Re: ignition switch question

    wsinsle,

    To check your ignition switch's proof circuit, you need to measure the resistance between the tab connector on the side of the switch and the ignition switch body. This is a GROUND circuit and not a power circuit.

    Coach Jack

     

    7/12/2018 8:13 PM  #6

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,711

    Re: ignition switch question

    coachJack wrote:

    wsinsle,

    To check your ignition switch's proof circuit, you need to measure the resistance between the tab connector on the side of the switch and the ignition switch body. This is a GROUND circuit and not a power circuit.

    Coach Jack

    My mistake, I checked to ground before but must not have checked in the start position. It does ground in the start position. Sorry for the misunderstanding.

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

    7/15/2018 2:11 PM  #7

    retired 65
    I FYI 24-7

    Offline

    From: nixa, mo.
    Registered: 4/02/2013
    Posts: 336

    Re: ignition switch question

    Thanks to everybody.  Since my old switch didn't have one, I think I won't worry about it.  If I do need a ground circuit etc., I might put a pigtail on it for future use.  Jerry

    "when I drop something, it always goes to center of the car"
       •Thread Starter
     

     

    1 of 1

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  »  ignition switch question

    • Board footera


    REMEMBER!!! When posting a question about your Mustang or other Ford on this forum, BE SURE to tell us what it is, what year, engine, etc so we have enough information to go on.