1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Has anyone measured voltage drop in headlight wiring on their 2nd gen?

Discussion in 'Lighting' started by iroc409, Aug 28, 2011.

  1. Aug 28, 2011 at 10:24 AM
    #1
    iroc409

    iroc409 [OP] Well-Known Member

    Joined:
    Jul 8, 2009
    Member:
    #19444
    Messages:
    446
    Gender:
    Male
    Washington
    Vehicle:
    A red one
    I am just curious if anyone has ever done this. I know a few people have created relay harnesses for the headlights, but can't remember if anyone checked the voltage drop first.

    I'm guessing there is some. There's a lot of stuff on the circuits, and I'm guessing (just from memory) the wiring is only 20-ga.
     
  2. Aug 28, 2011 at 10:42 AM
    #2
    cummins6speed

    cummins6speed Well-Known Member

    Joined:
    Jan 9, 2009
    Member:
    #12426
    Messages:
    1,809
    Gender:
    Male
    Vehicle:
    '05 4Runner Limited Edition
    Custom extended travel 2.5" King RR coilovers, 1.25" Camburg uniball uppers, homebuilt tube bumper
    The headlights are already on a relay. I doubt there is really any voltage drop on the wiring
     
  3. Aug 28, 2011 at 12:17 PM
    #3
    iroc409

    iroc409 [OP] Well-Known Member

    Joined:
    Jul 8, 2009
    Member:
    #19444
    Messages:
    446
    Gender:
    Male
    Washington
    Vehicle:
    A red one
    Yeah, I would think relays would reduce the drop considerably. However, there's a few other things running off the headlight circuit, like the fog relay, in-cab indicators, etc (and the tiny wiring). They're running between the headlight relay and the bulb.

    I was just curious, as I've thought about building a harness but don't really want to go to the expense. I'm upgrading my cheap aux fuse block and adding new auxiliary lights (had some on previously but wasn't happy with them), so I'm ordering parts.
     
  4. Sep 12, 2011 at 3:08 AM
    #4
    iroc409

    iroc409 [OP] Well-Known Member

    Joined:
    Jul 8, 2009
    Member:
    #19444
    Messages:
    446
    Gender:
    Male
    Washington
    Vehicle:
    A red one
    As an update, I was able to measure voltage drop on my headlights with the engine off and headlights on.

    Looks like about .45v drop on the driver bulb, and .75-.8v drop on the passenger bulb. More than I expected.
     

Products Discussed in

To Top