Peterbuilt 389, turning on the "fog" light on hi beam?

Discussion in 'Trucks [ Eighteen Wheelers ]' started by Garnotte, Jan 14, 2016.

  1. Garnotte

    Garnotte Bobtail Member

    Oct 5, 2014
    I got a new 389 pete, and the fog light only turn on while I swith to low beam. There is a way to make them turning on with HI beam without re-doing the entire wiring?

  2. Slowpoke KW

    Slowpoke KW Heavy Load Member

    Dec 7, 2015
    It's my understanding that dot regulations don't allow manufacturers to build it any other way the few four wheelers I've been around with fog lights were the same way. But I'm not an expert and don't use them darn lights anyway
  3. glitterglue

    glitterglue Light Load Member

    Jan 22, 2011
    Adair Village, OR
    Fog lights are illegal to be run at the same time as the high beams, in most, if not all, states.

    The auto-off when switching to high beams has been a manufacturer default for many years now.

    Use Google to find state specific DOT codes.
  4. AModelCat

    AModelCat Road Train Member

    Jul 7, 2015
    Caught in a Mosh
    Any truck or light vehicle I've been around has been the same way.
    OLDSKOOLERnWV Thanks this.
  5. swaan

    swaan Road Train Member

    Jul 12, 2009
    BC canada
    Fog lights yes
    Driving lights are other way .
    They come on with the high beams.
    This is how trucks are wired from the factory .
    Both my new WS 4900fa are. I ordered them with driving lights in the bumper.
    They come on with the high beams if switch is in the on position.

    I do know that if I ordered them with fogs ,it would of been low beam only.
  6. Garnotte

    Garnotte Bobtail Member

    Oct 5, 2014

    I'm not asking about the law, I just want how to do it! I don't drive in the USA anyway. My old truck had 2 driving led spot, 2400 lm each and they turned on when I switch to hi beam, then they close when i,m back on the low beam, so I don't blind anybody. "Fog" on low beam are just stupid, you switch to low beam to avoid blinding other road user, but the fog came on....sometime they are almost worst than the hi beam.

    In fac this truck didn't come with any lights, just 2 hole in the bumper and the wiring. I plan to install some spot light to light up the deers at night.
    Last edited: Jan 14, 2016
  7. swaan

    swaan Road Train Member

    Jul 12, 2009
    BC canada
    You should be able to jump the fog relay with a wire coming from the high beam relay. With out actually seeing what you got its hard to explain,but any good shop should be able to enable that feature for you with some small creative wiring.
    Should be all in your panel where your relays and fuses are. Get a test light and figure it out.
    Onemanshow and AModelCat Thank this.
  8. scottied67

    scottied67 Road Train Member

    Mar 14, 2010
    california norte
    Mine has separate switched for the fog lights and headlight lights. In fact I can turn off the headlights and run fog lights only. Often do that in truck stops at night as a courtesy to drivers sleeping.
  9. GrapeApe

    GrapeApe Road Train Member

    Jan 7, 2013
    On the 389's, the fog lights are controlled by the chassis node. It's not a hard thing to do, are you OK with basic wiring? You'll need to take the chassis node out the of the fog light circuit, add a relay and fuse for them.
  10. little cat 500

    little cat 500 Road Train Member

    Jan 17, 2010
    Abbottstown PA
    only allowed 4 lights on at a time high beams count as 4 lights
  • Draft saved Draft deleted