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  •  » head light relays

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    1/11/2022 6:25 PM  #1

    val fulesday
    I FYI 24-7

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    Registered: 9/23/2013
    Posts: 403

    head light relays

    I am trying to put relay's in my 64 falcon. I get the power wire and ground wire BUT I am totally lost when it comes to getting it wired up thru the dimmer switch. I need some serious help as I have looked at you tube and it just doesn't make any sense to me, as to how to get everything connected correctly thru the factory wiring harness.

     

    1/11/2022 6:47 PM  #2

    MS
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    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 11,733

    Re: head light relays

    You need a separate relay for high beams and low beams.
    Is my diagram still on the Tips and How-To page?

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    1/11/2022 8:02 PM  #3

    val fulesday
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    Re: head light relays

    I did a search and didn't see it, may have worded it incorrectly
     

       •Thread Starter
     

    1/11/2022 8:49 PM  #4

    BILLY WALTON from GEORGIA
    Carrollton, GA Bash Host

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    From: CARROLLTON GEORGIA
    Registered: 4/14/2013
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    Re: head light relays

    MS wrote:

    You need a separate relay for high beams and low beams.
    Is my diagram still on the Tips and How-To page?

    Looks to have disappeared with the 24 inch Radiator swap instructions.

    Its really me....I fixed my caps lock .
     

    1/11/2022 9:07 PM  #5

    BILLY WALTON from GEORGIA
    Carrollton, GA Bash Host

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    Re: head light relays

    val fulesday wrote:

    I did a search and didn't see it, may have worded it incorrectly
     

    https://fyi.boardhost.com/viewtopic.php?id=4312


     

    Its really me....I fixed my caps lock .
     

    1/11/2022 9:51 PM  #6

    val fulesday
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    Re: head light relays

    I went to "that other page" to the amazon link, clicked on it and it's disconnected,
     

       •Thread Starter
     

    1/12/2022 2:27 AM  #7

    Ron68
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    From: Mukilteo, Washington
    Registered: 4/01/2013
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    Re: head light relays

    Check out this link to JamesW's page http://midnightdsigns.com/james/headlights.htm

    68 coupe - 351W, 4R70W, 9" 3.25 -- 65 convertible - 289 4v, C4, 8" 3.00
     

    1/12/2022 5:33 AM  #8

    Nos681
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    From: Atlantic Mine, Michigan
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    Re: head light relays

    Here’s another write up too.

    https://fyi.boardhost.com/viewtopic.php?id=11632

     

    1/12/2022 9:48 AM  #9

    6sally6
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    From: Surfside Beach,SC
    Registered: 4/02/2013
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    Re: head light relays

    Ron68 wrote:

    Check out this link to JamesW's page http://midnightdsigns.com/james/headlights.htm

    I used this one (many-moons-ago!) Breaks it down pretty simple.
    6s6
     

    Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
     

    1/12/2022 10:11 AM  #10

    BobE
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    From: White Plains, NY
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    Re: head light relays

    Here is my diagram, wire numbers/colors relate to 65-66 Mustangs, but likely are the same for Falcons.  I mounted the two relays next to the radiator on the driver's side where the OEM voltage regualtor had been.  All  splices were made in that area.  I also powered the headlights via a new independent 15 amp circuit breaker that was fed from the positive post off the starter solenoid.  This way, the power from headlight switch circuit breaker only powers the headlight relays. 


     

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

    1/12/2022 12:21 PM  #11

    Rufus68
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    From: Knoxville, TN
    Registered: 4/26/2017
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    Re: head light relays

    No splices are necessary if you buy a headlight harness.  To connect to the car, unplug both headlights then plug one headlight connector into the harness.  The harness will contain 2 new connectors that you will plug into the bulbs.  You will wire the relays to power and ground.  The harness includes a fuse so you can connect the red wire directly to the battery if you wish.

    https://www.amazon.com/Partsam-Headlight-Harness-Compatible-Headlights/dp/B078XV8PL7/ref=sr_1_3?keywords=h4+headlight+relay+harness&link_code=qs&qid=1642011504&sourceid=Mozilla-search&sr=8-3
    .
    Look at the 3 connectors below.  One matches the back of your current bulb.  The other 2 match the current connectors on your car:


     

    Last edited by Rufus68 (1/12/2022 12:22 PM)

    1968 T-code Coupe with a 302.  Nice car, no show stopper for sure, but I like it.
     

    1/12/2022 12:35 PM  #12

    wsinsle
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    From: Belle Vernon, PA
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    Re: head light relays

    Ron68 wrote:

    Check out this link to JamesW's page http://midnightdsigns.com/james/headlights.htm

    The schematic at the bottom of this link has the diodes in the wrong spot. They should be connected to 86 not 30. Dan's post is correct.

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

    1/12/2022 1:18 PM  #13

    val fulesday
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    Re: head light relays

    I really appreciate the help but I wanted to keep the relays in the and run thru the dimmer switch, nothing I have seen allows this to be what i'd like to do. what i'm wanting to do can it be done or am I just "spitting in the wind"?

       •Thread Starter
     

    1/12/2022 1:40 PM  #14

    Bolted to Floor
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    Re: head light relays

    Both drawings called out diodes for the relays. One noted diodes were needed for EFI cars. Anyone care to explain the need for the diode? My Holley hasn't missed them. 

    John  -- 67 Mustang Coupe 390 5 speed
     

    1/12/2022 1:41 PM  #15

    BobE
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    Re: head light relays

    val fulesday wrote:

    I really appreciate the help but I wanted to keep the relays in the and run thru the dimmer switch, nothing I have seen allows this to be what i'd like to do. what i'm wanting to do can it be done or am I just "spitting in the wind"?

     Val - the sketch I provided runs through the original dimmer switch.

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

    1/12/2022 1:41 PM  #16

    Bolted to Floor
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    Re: head light relays

    val fulesday wrote:

    I really appreciate the help but I wanted to keep the relays in the and run thru the dimmer switch, nothing I have seen allows this to be what i'd like to do. what i'm wanting to do can it be done or am I just "spitting in the wind"?

    You want to keep the relays where? 
     

    John  -- 67 Mustang Coupe 390 5 speed
     

    1/12/2022 2:05 PM  #17

    mjacobs
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    From: Crossville Tn
    Registered: 2/07/2014
    Posts: 86

    Re: head light relays

    kit also available from Amazon

    Hella Part# 329.317-011

    Suggested by MS in the Past. I have installed and used without issues. Plugs directly into headlight harness and works perfectly with dimmer switch.
    high quality IMOP

    thanks

     

    1/12/2022 2:33 PM  #18

    Rufus68
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    From: Knoxville, TN
    Registered: 4/26/2017
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    Re: head light relays

    Using a harness is just plug-n-play.  No need to modify car.  Why make it more complicated?

    1968 T-code Coupe with a 302.  Nice car, no show stopper for sure, but I like it.
     

    1/12/2022 5:21 PM  #19

    val fulesday
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    Re: head light relays

    I am wanting to keep the relays inside the car , on the fire wall

       •Thread Starter
     

    1/12/2022 5:35 PM  #20

    Rufus68
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    From: Knoxville, TN
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    Re: head light relays

    I really think you're making this much more difficult than it needs to be; however, the output of the dimmer switch powers the relays so connections need to be made after the dimmer switch.
    .
    To get the benefit of the relays, the power to the headlights should not use the old wires, so you'll need to run new wires from inside to the headlights.  It would still probably pay you to buy a harness for the components.  I actually think you should consider if all of this effort will actually result in a worse solution. My opinion is that using a harness and not modifying the car's wiring is the best.  Of course, your car so your solution.
     

    1968 T-code Coupe with a 302.  Nice car, no show stopper for sure, but I like it.
     

    1/12/2022 7:08 PM  #21

    val fulesday
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    Re: head light relays

    t Rufus 68 the wiring harness you first suggested will not work on a falcon, so it says. and leave it to me to take a perfectly simple idea and make it difficult. plus I already have the relays and wire in the garage..
     

       •Thread Starter
     

    1/12/2022 8:12 PM  #22

    Bullet Bob
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    Re: head light relays

    Bolted to Floor wrote:

    Both drawings called out diodes for the relays. One noted diodes were needed for EFI cars. Anyone care to explain the need for the diode? My Holley hasn't missed them. 

    The diodes across the relay coils provide a path to ground for the reverse pulse created when a coil de-energizes.  Most Bosch type relays like I use have a resistor across internally across the coil which serves the same purpose.  The only diode I had to install was in the AC clutch circuit.  When the AC would cycle at idle the engine would instantly shut off.  I stuck a Ford diode, as they used in the factory Power distribution box so that negative on the positive lead would be shunted to ground.  Problem solved.

    Again:  I have a number of circuit drawings and explanations for a number of electrical modifications, including the relay-switched headlights and will gladly email them to anyone who PMs a email addy to me.

    BB1

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

    1/12/2022 8:23 PM  #23

    wsinsle
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    From: Belle Vernon, PA
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    Re: head light relays

    Bolted to Floor wrote:

    Both drawings called out diodes for the relays. One noted diodes were needed for EFI cars. Anyone care to explain the need for the diode? My Holley hasn't missed them. 

    I'm not a EFI guy nor do I play one on TV but I don't see any advantage to the diodes in the James W link. Maybe someone with EFI experience can explain. The diodes in NOS681's link has nothing to do with EFI. His diagram shows the diodes across the relay coils. When a coil is energized it build up energy. When it de-energizes, that voltage has to dissipate somewhere. This is usually across the switch contacts, (high/low beam switch) and can destroy contacts over time. The diode dissipates the voltage and helps save the switch contacts. Just trying to splain what the diodes are for, Bob E's diagram without diodes will work fine too.

    Val fulesday, all 3 diagrams posted will use the stock high/low beam switch. If you are having trouble following these diagrams and have stock wiring, I would just buy the prewired harness as posted. To be honest, I've been messing with electricity sense I was 8, if I had stock wiring, I would use the prewired set posted. Guess I'm getting to old and fat to do it myself.

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

    1/12/2022 8:41 PM  #24

    Nos681
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    Re: head light relays

    The diode protects the relay contacts as well as any electronic sensitive equipment connected.

    Although this video pertains to 5 volt system, it still applies to 12 volt systems as well.

    https://youtu.be/oMjNsoG6ZIA

    Higher quality relays like Ford (probably all car manufacturers) and Bosch have diodes built in across the coil.

    If a relay doesn’t have it, it would behoove you to add one.

    I would verify relays used for electric fans have a diode or in wiring harness.
    (A/C clutch coil)

    Ford also had a blocking diode for foxbody a/c compressor in the harness.
    Electric motors sending spikes through the system can cause problems too.

    Foxbody starter solenoids also have a diode in them.
    (Diode suppressed on housing usually)

    Last edited by Nos681 (1/12/2022 8:56 PM)

     

    1/12/2022 8:56 PM  #25

    Rufus68
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    From: Knoxville, TN
    Registered: 4/26/2017
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    Re: head light relays

    val fulesday wrote:

    t Rufus 68 the wiring harness you first suggested will not work on a falcon, so it says. and leave it to me to take a perfectly simple idea and make it difficult. plus I already have the relays and wire in the garage..
     

    The Falcon takes a standard H6024 bulb.  This harness has the correct connectors for that type of bulb so it will work.  Just because it doesn't specifically list a Falcon doesn't imply that it won't work on a Falcon.  It says it will work on any car that uses this type of connector which the Falcon does. 

    I hope this helps.

    Edit:  I'm sorry if this discussion sounds like it is just dragging on.  I don't mean it to be.  It's just that the task of adding headlight relays to our style of headlight connector is so simple using the available harnesses that I didn't want you to misunderstand the option available to you.  You don't need to alter the existing car wiring.  You only need to install a harness and plug in the headlights, job done.
     

    Last edited by Rufus68 (1/12/2022 9:04 PM)

    1968 T-code Coupe with a 302.  Nice car, no show stopper for sure, but I like it.
     

     

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