Announcement

Collapse
No announcement yet.

High beams and low beams lit simultaneously

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • High beams and low beams lit simultaneously

    Is it It is technically feasible to make the high beams and low beams lit simultaneously on H4 car? Particularly, when installing a projector headlamp that has H1 or H7 bulbs to an H4 car. I ask this because I've noticed that the low beam turns off when the high beam lights up. Here's an example of what I mean:

    https://youtu.be/2EULDznS4EY?t=257

  • #2
    By convention, H4 halogen bulbs alternate between igniting the low beam and high beam filaments. Since the bulb has 3 pins, it is electrically possible to have both on at the same time. However, as the bulb wasn't designed to sustain both filaments energized at the same time, you can run the risk of the bulb blowing out due to insufficient heat dissipation.

    Suppose early failure is not an issue, having a custom harness that can provide power to both filament simultaneously should work.
    Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

    3-way quad wiring; foreground limiter; squirrel finder;

    Comment


    • #3
      Originally posted by satrya View Post
      By convention, H4 halogen bulbs alternate between igniting the low beam and high beam filaments. Since the bulb has 3 pins, it is electrically possible to have both on at the same time. However, as the bulb wasn't designed to sustain both filaments energized at the same time, you can run the risk of the bulb blowing out due to insufficient heat dissipation.

      Suppose early failure is not an issue, having a custom harness that can provide power to both filament simultaneously should work.
      It's true, these are risks for the stock headlamps. What I will do is I will install aftermarket projector headlights to my car, which takes H1 bulbs. The headlights I mention will be something like the ones in this car:

      https://youtu.be/2EULDznS4EY?t=203
      Last edited by xnfot; November 21st, 2019, 12:04 PM.

      Comment


      • #4
        There are several vendors that offer wiring kits for this purpose. You'll need an additional wire to the battery. You should be able to get them from TRS or China.
        Subaru Outback retrofit:
        http://www.hidplanet.com/forums/show...aru-Outback-H6
        License plate lights with dual brightness:
        https://www.hidplanet.com/forums/for...hen-backing-up

        Comment


        • #5
          Originally posted by Crossgolf View Post
          There are several vendors that offer wiring kits for this purpose. You'll need an additional wire to the battery. You should be able to get them from TRS or China.
          Is there a specific kit from TRS? I checked the wiring section and couldn't figure out...

          It's a whole new level of modding! I haven't done anything like this before. Anyone else had experience with such modding?

          Comment


          • #6
            https://www.theretrofitsource.com/mo...n-h4-9003.html

            The h4 harness will do it for you.

            Depending on the car it might also be very easy to change the setup. I remember on my Volkswagen Golf Mkiii I only had to add a little bridge in the relay compartment under the dash. But the golf was available with H4 and H1 / H1 from the factory.
            Subaru Outback retrofit:
            http://www.hidplanet.com/forums/show...aru-Outback-H6
            License plate lights with dual brightness:
            https://www.hidplanet.com/forums/for...hen-backing-up

            Comment


            • #7
              Edit: maybe your aftermarket headlights come with a solution for your problem already since every customer should have this very specific problem.
              Subaru Outback retrofit:
              http://www.hidplanet.com/forums/show...aru-Outback-H6
              License plate lights with dual brightness:
              https://www.hidplanet.com/forums/for...hen-backing-up

              Comment


              • #8
                What car are you working on? If it's Toyota you may just need a basic relay harness, no motocontrol etc. type module needed
                Originally posted by HK45
                I don't even look to see what Eddie writes anymore. I'm too busy staring at his avatar.

                Comment


                • #9
                  Originally posted by Eddie View Post
                  What car are you working on? If it's Toyota you may just need a basic relay harness, no motocontrol etc. type module needed
                  I'm working on a Fiat Grande Punto (Type 199). It has canbus system and it wears stock H4 headlights. What's interesting though is that the car wire connects first to a certain plug (as shown on the left):

                  1.






                  2.







                  Then it goes to the H4 bulb connector wire. Something like this:


                  3.







                  With that said, even the aftermarket headlights (the ones I'm planning to buy) have the same plug as well as the one seen on the first image...










                  Will that make it more complicated?
                  Last edited by xnfot; November 22nd, 2019, 06:13 PM.

                  Comment

                  Working...
                  X