High beam mod write up

Discussion in 'How-to Guides' started by bartlett, May 26, 2009.

  1. bartlett

    bartlett New Member

    this mod lets your low beams stay on when you turn on your high beams. This is for 88-98 models only though.


    1. 4 prong relay(#85,#86,#87,#30 prongs)
    2.16 gauge wire (4 different colors Green,Brown,Red,Black)
    3. conduct
    4. electrial tape
    5. self tapping screw
    6. 4 female wire connectors
    7. 1 ring terminal for battery
    8. 1 ring terminal for ground
    9. 2 side by side wire connectors
    10. 1 inline fuse

    Most of these items I already had. I think I only spent like $10 total.
    You can get the relay and everything else at autozone.


    The wires that you need to splice into are located between the battery and the pass. side headlight.
    It is not nessecary to remove the headlight but removing the grille will definatley make it easier to access the wires.

    1. Using 1 side by side connector clip a length of brown wire to the brown wire of low beams.
    2. using the other side by side connector clip a length of green wire to green wire of high beams.
    3. make sure you leave enough wire to run to the relay.
    4. locate the relay on the fenderwell, the closer to the battery the better.
    5. using the self tapping screw, attach the relay to the fenderwell.
    6. Run brown wire to #87 on relay with female connector.
    7. Run green wire to#86 on relay with female connector.
    8. Run black wire for ground to fenderwell( I found a bolt that was close to attach the ground. Or
    you could use another self tapping screw.)
    9. attach ground wire to #85 on relay.
    10. Run red wire from #30 on relay to inline fuse then to positive battery terminal.
    11. Wrap wires in conduct, secure ends with electrial tape.
    12. Reassemble everything and your done.
    Last edited: May 27, 2009
  2. GaryL

    GaryL Epic Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    Great write up, I will try it on my Suburban.

    I renamed the title to make it a little more clear (I thought it was a 4wd high mod) and moved it to the "How-To" section.


    99'HEARTBEAT MODERATOR Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    Last edited: Aug 7, 2011
  4. bartlett

    bartlett New Member

    This way is only done on the passenger side. The wires are tied together, from drivers side to pass. side.
  5. roger97338

    roger97338 Member

    Awesome! Thanks for the write-up! I've seen the kits for this for later model trucks, but none for my '75. I'll be doing this very, very soon!
  6. pontiacGTP123

    pontiacGTP123 Rockstar 100 Posts

    great write up
  7. Snyder729

    Snyder729 Rockstar

    Great write up thank you =D i actualy did this the day after i read it.
  8. egreg

    egreg Rockstar

    This method isn't working on my truck, and I'm having issues getting it back to normal now. I may have hooked up a wire wrong, but I think it's right. When I have the relay set up everything works like normal, but no 4hi. It effectively accomplishes nothing. When I turn the truck off I have to disconnect the +12v to get the low beams to turn off. When I tried to revert back to stock I am getting extremely low voltages from my headlights on the drivers side (the side I did the mod on) now. Any clues?

    DAREDEVIL Rockstar 4 Years 1000 Posts

    This is a very cool write up. ............BUT, i got mine from JEGS, for 25 bucks including shiping .
    I could not find relays for that money and @ JEGS everything is included. :glasses:

    Still, very cool info. THANKS
  10. 1RAD

    1RAD New Member

    Anything like this for the '04??? I would love to do this.

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