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
  •  » Any idea what this firewall hole/wire is for above the brake MC?

    • 1 of 1

       

    6/10/2021 12:47 PM  #1

    mustang6518
    FYI FORD Member

    Offline

    Registered: 2/15/2021
    Posts: 31

    Any idea what this firewall hole/wire is for above the brake MC?

    Got my interior back together, and have a leftover black bullet plug wire in the interior under my dash. It goes out the firewall via its own dedicated hole, above the master cylinder (circled in red here). Anyone know what this is for? The car was originally AC, but I don't have it installed any longer, so wondering if it was for that... 

    Picture is below

    Last edited by mustang6518 (6/10/2021 12:48 PM)

     

    6/10/2021 1:00 PM  #2

    BobE
    Senior 24-7 FYI Addict

    Offline

    From: White Plains, NY
    Registered: 4/04/2013
    Posts: 2,645

    Re: Any idea what this firewall hole/wire is for above the brake MC?

    My 65 does not have this hole, and did not have factory AC.  I'm guessing that this may be for the AC compressor clutch.  To my knowledge, the only other single-wire electric penetration in the firewall was for the windshield washer pump, that was located closer to the where the throttle lever is located.

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

    6/10/2021 1:15 PM  #3

    lowercasesteve
    Senior 24-7 FYI Addict

    Offline

    From: Auburn, Ca
    Registered: 4/01/2013
    Posts: 1,253

    Re: Any idea what this firewall hole/wire is for above the brake MC?

    I agree with BobE.  Windshield washer pump.  On my '66 that wire appears to go to the washer pump.  I cannot tell for sure as the wire goes into a bundle that I can't follow.  But the washer wire going into the washer appears to be the same wire.  Mine has a grommet in that hole.  Looks like yours needs one too.

    Original owner - 351w,T-5, 4whl disks, power R&P
     

    6/11/2021 6:50 AM  #4

    Nos681
    Senior 24-7 FYI Addict

    Offline

    From: Atlantic Mine, Michigan
    Registered: 7/14/2016
    Posts: 3,333

    Re: Any idea what this firewall hole/wire is for above the brake MC?

    Washer pump on my July built 65 in San Jose.
    Should end front of LH shock tower and aft of washer bag location.
    Mine had the 3 tab washer motor.
    Inside, went to single speed wiper switch.
    If you pull, should have 12v on that wire.

    Last edited by Nos681 (6/11/2021 6:55 AM)

     

     

    1 of 1

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  »  Any idea what this firewall hole/wire is for above the brake MC?

    • 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.