1991 379 electrical issues

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Coolbreezin, Oct 22, 2020.

  1. Coolbreezin

    Coolbreezin Light Load Member

    224
    160
    Jun 11, 2016
    Florida
    0
    Hey all. My idiot lights no longer illuminate, my electric gauges no longer work and my jakebrake doesnt work. However, sometimes everything will operate correctly for about 5 miles. Ultimately my engine fan switch governs it all. I thought maybe a wire issue but bouncing has no effect. I changed the switch and no better. Sometimes it'll all start working while I sit and idle. I reached in my dash and jiggled wires around by the handfull, nothing. Since it works sporadically, it's not a fuse. Im not an electrical person. Any advice?
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. BoxCarKidd

    BoxCarKidd Road Train Member

    3,010
    3,937
    Aug 26, 2014
    0
    A little different deal but similar with the manual fan switch light coming on with a Pete. Make sure all the battery cable connections are clean and tight.
    Your deal sounds different but that is easy to check. The truck I worked on would shut down while driving and it had one loose battery connection. Truck had under 100,000 miles.
     
  4. Goodysnap

    Goodysnap Road Train Member

    2,030
    4,426
    Jul 12, 2017
    0
    Your going way back on me.

    Check the 150 amp breaker driver side of the dash top. See if you have good power to both sides when its broken.
     
    pushbroom Thanks this.
  5. Coolbreezin

    Coolbreezin Light Load Member

    224
    160
    Jun 11, 2016
    Florida
    0
    If the fuse yr speaking of is popped, the dash wouldnt come to life at all. It works sporadically for a few miles.
     
  6. Coolbreezin

    Coolbreezin Light Load Member

    224
    160
    Jun 11, 2016
    Florida
    0
    UPDATE: after digging through the dash for a while I climbed out of the truck and noticed the fuse box had a tripped breaker I pushed it back in and also found that the "dash panel" fuse was popped. Fixed those two and dash works fine. But now it raises the question why did the dash work sporadically?

    Like "how many licks does it take to get the the center of a Tootsie pop" kinda question. Guess the world will never know.
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  • Draft saved Draft deleted