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

ORTATTW switch and dimmers

Discussion in 'Lighting' started by Monkeyboy, Apr 21, 2013.

  1. Apr 21, 2013 at 4:30 PM
    #1
    Monkeyboy

    Monkeyboy [OP] Well-Known Member

    Joined:
    Sep 16, 2011
    Member:
    #63637
    Messages:
    494
    Gender:
    Male
    Grand Junction, CO
    Vehicle:
    2012 AC TRD Sport
    Hey - I searched, but wasn't able to find the answer to this question :

    I have an ORTATTW switch - and getting it to light up is easy enough. However, if I tie it to the dimmer circuit, it works backwards. Dimming the lights makes the switch brighter, and vice versa.

    So, how can I make the ORATTAW switch work correctly with the stock dimmer ?
     
  2. Apr 21, 2013 at 4:43 PM
    #2
    KeithB

    KeithB Well-Known Member

    Joined:
    Jan 6, 2009
    Member:
    #12299
    Messages:
    636
    Gender:
    Male
    First Name:
    Keith
    Cheshire, CT
    Vehicle:
    SWB '09 Tacoma DCSB Sport 4x4
    Wheels and Tires: 17x8" Ultra Goliath wheels with P285/70R17 Nitto Terra Grappler G2, Suspension: Icon coilovers set at 2.5", TC UCA's, 1.5" lift 3 leaf pack with overload left in, 3* shims, carrier bearing drop, Bilstein 5100 B110 rear shocks Other: TRD SS exhaust, Ottonavi H/U with Sat radio, bluetooth, ipod interface, DVD, Navigation Accessories: Toyota roof rack, black Toyota running board steps, cargo divider, weathertech floor liners, Literider roll up soft tonneau, thule bars over tonneau Cosmetic: window tint, grillcraft black mesh upper/lower grill, eyelids, tinted tails and third brake light, vinyl armrest in doors Lighting: fogs only mod, bed lights in pockets, back up lights, amber interior accent lighting, amber 10" LED light bar in hood scoop, 33" LED bar behind the lower grill, amber lamin-x on fog lights
    No idea! Maybe reverse the wires?
     
  3. Apr 21, 2013 at 4:45 PM
    #3
    Monkeyboy

    Monkeyboy [OP] Well-Known Member

    Joined:
    Sep 16, 2011
    Member:
    #63637
    Messages:
    494
    Gender:
    Male
    Grand Junction, CO
    Vehicle:
    2012 AC TRD Sport
    Ok, thinking about this - the stock switches must ground through the dimmer.

    Green wire = hot when lights on. White/green = 0(on) to 12v(dimmed).

    So, if I ground the switch to White/green, it would work.

    However, the ORATTW switches have a common ground for the switch and the lights. So, I can't ground to White/Green or bad things will happen. Therefore, I don't think it is possible to have this switch be dimmed.
     
  4. Jul 14, 2013 at 11:50 AM
    #4
    Monkeyboy

    Monkeyboy [OP] Well-Known Member

    Joined:
    Sep 16, 2011
    Member:
    #63637
    Messages:
    494
    Gender:
    Male
    Grand Junction, CO
    Vehicle:
    2012 AC TRD Sport
    So, not content to not have dimmed aftermarket switches, I designed a simple difference amplifier circuit.

    Input 1 is the 12v lighting circuit. Input 2 is the variable 0-12v lighting circuit (dimmer). The output is the difference between the two.

    R1, R2, R4, and R5 all need to be the same values, but it doesn't really matter what they are. There are a bunch of op amps that will work for this; I've got some TLC272 left over from a different project so I used that.

    I've test benched this circuit on breadboard and it works OK. I need to get some parts and build it to test in the truck, but it should work.




    [​IMG]
     
    Last edited: Jul 14, 2013
To Top