WST 4900FA turn signal problem

Discussion in 'Western Star Forum' started by Pilotsfp, May 6, 2022.

  1. Pilotsfp

    Pilotsfp Bobtail Member

    1
    0
    May 6, 2022
    0
    I got a 2012 western star 4900 FA, recently notice a problem that if the truck is running and headlight/ marker light it’s on, right side turn signal will not work, both front and back, and there’s a very dim turn signal light on the dash constantly.

    Tested the voltage from the turn signal, between control wire and ground has constant 4.5 volt when turn signal is on, all voltage is normal if truck is off and headlight/marker light off.

    Checked the ground is good, 2 ohm. The wiring near the front headlight and turn signal is good.

    Anyone has similar problems or has ideas what is wrong?
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. Shoemake420

    Shoemake420 Bobtail Member

    1
    0
    Dec 18, 2023
    0
  4. fortycalglock

    fortycalglock Road Train Member

    6,155
    6,584
    Jun 25, 2011
    Tourist Town, FL
    0
    If anyone looks at this in the future, a new ground wire at the taillights solved this for me a long time ago.
     
    Hammer166 Thanks this.
  5. DougP

    DougP Bobtail Member

    1
    0
    Jul 6, 2020
    0
    Did anyone figure out this problem?? I have the exact same issue as listed above
     
  6. Hammer166

    Hammer166 Crusty Information Officer

    7,461
    27,046
    Aug 18, 2007
    ~8600+' and loving it!
    0
    It's a ground issue. Could be in the fixture, could be wiring. The marker is grounding through the turn circuit either due to an internal fault or a faulty ground.
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.