Key to power position blows CECU BATT POWER 1

Discussion in 'Trucking Electronics, Gadgets and Software Forum' started by zaroba, Sep 16, 2020.

  1. zaroba

    zaroba Heavy Load Member

    840
    1,269
    Aug 28, 2012
    South East PA
    0
    Paccar mx13, 2016 t680 with 472k miles.

    I replace the 15amp fuse and 2 or 3 engine starts later it blows again. If I replace it with the engine already running it's fine so can't see it being a short or it would blow going down the road from bumps/vibration. It only blows when the key is toggled to power before starting the engine.

    Alt and batts seem fine, just under 14volts running and 12 volts when shut off, so guessing something to do with power distribution.

    Any thoughts?
     
    Last edited: Sep 16, 2020
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. 062

    062 Road Train Member

    6,208
    33,438
    Oct 20, 2013
    0
  4. Goodysnap

    Goodysnap Road Train Member

    3,716
    9,022
    Jul 12, 2017
    0
    Wont be easy to track down. Any moisture or evidence of water inside any of the CECU connectors? May not be a short but rather an over amperage situation. Disect the wiring schematic, checking the circuit for continuity to ground and see if it branches anywhere else other than the CECU that may lead you to the source of excess amp draw on the circuit.
     
    spsauerland and 062 Thank this.
  5. spsauerland

    spsauerland Road Train Member

    4,296
    10,887
    May 31, 2010
    West Harrison, In
    0
    Exactly which fuse (picture of location) and last six of VIN.
     
    062 Thanks this.
  6. zaroba

    zaroba Heavy Load Member

    840
    1,269
    Aug 28, 2012
    South East PA
    0
    Fuse k18, CECU BATT PWR 1
    Last 6 of vin is 454381

    20200916_182711.jpg 20200916_183328.jpg


    All it powers is these 4 gauges and the dial thing in the bottom left to scroll through the menu on the instrument panel, so it's not a major issue.

    20200916_182929.jpg
     
  7. spsauerland

    spsauerland Road Train Member

    4,296
    10,887
    May 31, 2010
    West Harrison, In
    0
    Here is the diagram. If wiring checks ok, I would try unplugging gauges and MCS one @ a time to see what is pulling excess amperage. Someone that could hook up with ESA might get you some more clues.
     

    Attached Files:

    Goodysnap Thanks this.
  8. Tylerelliott93

    Tylerelliott93 Bobtail Member

    1
    0
    Sep 30, 2023
    0
    I was wondering if you ever came up with a solution. I have a truck doing the exact same thing
     
  9. Hen265

    Hen265 Bobtail Member

    1
    0
    May 17, 2024
    0
    Did you ever figure the problem? I have a truck doing the exact same thing
     
  10. dbtractor

    dbtractor Bobtail Member

    3
    0
    Dec 4, 2024
    0
    The batt 1 wire to the cecu only goes to one place which is the cecu. Only a few things I see that could blow the fuse, one is something is wrong inside the pdc which is unlikely but possible. the wire between the pdc and cecu has a rubbed point on metal somewhere in the dash. or the cecu is failing and draws too much current on the batt 1 circuit once supplied an ignition wakeup signal and powers up. you could isolate the ignition wakeup and supply you own with a jumper form the battery and see if the fuse blows.
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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