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  •  » 12v power source

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    8/30/2020 2:50 PM  #1

    1fststang
    I FYI 24-7

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    Registered: 6/02/2013
    Posts: 419

    12v power source

    Where do you guys like to hook your 12 v power for things like msd box, electric fan etc ?

    I usually like to run mine to the battery side of the solenoid but apparently the new solenoid  has a shorter stud than what i usually see so the stud doesn't have enough room to run many ring terminals to it.

    i have in the past ran them to the battery clamp bolts but doesn't look as clean as i like.

    My optima has side terminals that i could use so may try that or pick up another solenoid.

    Also I have several things like the msd and fans that need 12v from ignition source. Do you guys run all these components back to the ignition switch or can you run to the I terminal on the solenoid ?

     

    8/30/2020 3:20 PM  #2

    BobE
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    From: White Plains, NY
    Registered: 4/04/2013
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    Re: 12v power source

    I use the battery side of the solenoid as you indicate.  You can purchase a remote mounted stud, 5/16" diameter, they come in red and black, and connect it to the battery side of the solenoid, and run additional circuits from that point. 
    You need to go back to the ignition switch.  The "I" post on the solenoid is only energized when the solenoid is energized to provide power to the starter.  The "I" terminal provides full 12v to the ignition coil to gave a extra boost for starting.  The ignition switch, in the 'run' position, connects to a resister wire that drops voltage to the coil to about 9v.  You need to connect to this circuit prior to the resister wire (a single plug connector on the early Mustangs), or you can connect to the "Accessory" terminal.  A word of caution, when the ignition switch is in the 'accessory' position, those components connected to it will be energized.

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

    8/30/2020 4:59 PM  #3

    1fststang
    I FYI 24-7

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    Registered: 6/02/2013
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    Re: 12v power source

    Since the fans and the msd have separate thicker gauge power and ground I'm assuming the separate 12v ignition power is just a signal to let the msd or fans know the car is in run mode ?

    Would it make since to add a single power distribution block that feeds from engine compartment to ignition and run anything that needs 12v ign to it ?
     

       •Thread Starter
     

    8/31/2020 5:10 AM  #4

    TKOPerformance
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    From: Newark, DE
    Registered: 12/15/2014
    Posts: 7,504

    Re: 12v power source

    If you plan to add a lot of accessories that will need both constant 12V and keyed 12V it a good idea to add a junction of some sort.  This prevent you from having a bunch of wires running haphazardly.

     

    8/31/2020 6:22 AM  #5

    Bullet Bob
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    From: Montrose, Colorado
    Registered: 4/01/2013
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    Re: 12v power source

    I prefer a fused heavy source from the solenoid or alternator lug to a block of relays which are triggered by the "C" and/or "Acc" lug of the Ignition switch, depending on when I want them energized.  I run a Maxi-Fuse protected 80 amp source from the battery to a power distribution box which contains various relays circuits which are individually fuse protected.  Yeah, it's a lot of work but it's reasonably clean and very reliable. 

    BB1

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

    9/01/2020 6:05 PM  #6

    rhutt
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    From: Santa Clarita, CA
    Registered: 1/10/2017
    Posts: 109

    Re: 12v power source

    I ran into the same problem on my solenoid. With all the add-ons that required 12v power, I found a temporary solution that has worked so well that it has become permanent.
    I replaced the retaining nut that came on the solenoid with a coupling nut. After securing half of my connections, I tightened it down and bottomed a long set screw to the solenoid post. With 1/2"-3/4" protruding, I placed the remainder of my connections on set screw and anchored them with the original solenoid nut.

    Last edited by rhutt (9/01/2020 6:07 PM)

    '66 GT Fastback, 302, Edelbrock top end, Sniper EFI, MSD, JBA Headers & Exhaust, T-5Z, Currie 3.55 Trac-Loc
     

    9/01/2020 6:24 PM  #7

    Raymond_B
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    From: Fort Worth, TX
    Registered: 4/01/2013
    Posts: 1,208

    Re: 12v power source

    Bullet Bob wrote:

    I prefer a fused heavy source from the solenoid or alternator lug to a block of relays which are triggered by the "C" and/or "Acc" lug of the Ignition switch, depending on when I want them energized.  I run a Maxi-Fuse protected 80 amp source from the battery to a power distribution box which contains various relays circuits which are individually fuse protected.  Yeah, it's a lot of work but it's reasonably clean and very reliable. 

    BB1

    This! You want as little 12V hot when the key is off as possible and what will remain hot needs to be fused.

    I ran this Bussman relay fuse block with 6ga wire fused from the battery.The red fuse blocks are also Bussman from Waytek. They are pretty cool and interlock so you figure a middle bussbar and then how many fuses you want off of it. Makes a nice splitter as well.

    [img]




     

    Last edited by Raymond_B (9/01/2020 6:27 PM)

     

    9/01/2020 9:45 PM  #8

    Cab4word67
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    From: Portland, Ore
    Registered: 4/06/2019
    Posts: 1,154

    Re: 12v power source

    On my 65 I added a 2 post Positive block on the inner fender between my Amp & Alt fuses, then taped the needed Acc from it. I also ran a #6 from the block through the core support to the driver side where the Fan controller is, giving me 2 Positive post under the hood

    Last edited by Cab4word67 (9/01/2020 9:56 PM)

    Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     

    9/03/2020 11:57 AM  #9

    True74yamaha
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    From: Salt Lake City
    Registered: 5/07/2013
    Posts: 2,529

    Re: 12v power source

    Cab4word67 wrote:

    On my 65 I added a 2 post Positive block on the inner fender between my Amp & Alt fuses, then taped the needed Acc from it. I also ran a #6 from the block through the core support to the driver side where the Fan controller is, giving me 2 Positive post under the hood

    I noticed you have an electric fan controller how do you like it?

     

    9/03/2020 7:06 PM  #10

    HudginJ3
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    From: Cedar Hill, TX
    Registered: 4/29/2015
    Posts: 1,249

    Re: 12v power source

    I notice you are running the PA Performance regulator. I couldn't get mine to work. I opened up and the was nothing hooked up inside of it. It had wires but they were all cut. 

    70, ragtop 351W/416 stroker Edel Performer heads w pro flow 4, Comp roller 35-421-8. T5
     

    9/05/2020 1:55 PM  #11

    Cab4word67
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    From: Portland, Ore
    Registered: 4/06/2019
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    Re: 12v power source

    True74yamaha wrote:

    Cab4word67 wrote:

    On my 65 I added a 2 post Positive block on the inner fender between my Amp & Alt fuses, then taped the needed Acc from it. I also ran a #6 from the block through the core support to the driver side where the Fan controller is, giving me 2 Positive post under the hood
    Best fan controller I think there is out there. Got mine from someone on our forum that wasn't building the car anymore. 

    I noticed you have an electric fan controller how do you like it?

     

    Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     

    9/05/2020 2:00 PM  #12

    Cab4word67
    Senior 24-7 FYI Addict

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    From: Portland, Ore
    Registered: 4/06/2019
    Posts: 1,154

    Re: 12v power source

    True74yamaha wrote:

    Cab4word67 wrote:

    On my 65 I added a 2 post Positive block on the inner fender between my Amp & Alt fuses, then taped the needed Acc from it. I also ran a #6 from the block through the core support to the driver side where the Fan controller is, giving me 2 Positive post under the hood
    Best fan controller I think there is out there. Got mine from someone on our forum that wasn't building the car anymore. 

    I noticed you have an electric fan controller how do you like it?

     

    Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     

     

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