Truckers Report Jobs

Find Trucking Jobs

Company Driver Company Driver Dry Van Dry Van Flatbed Flatbed Refrigerated Refrigerated Specialized Specialized Owner Operator Owner Operator
More Trucking Job Searches ⌄ Fewer Trucking Job Searches
⌃

Tachometer is Intermittent

Discussion in 'Freightliner Forum' started by Johnsf, Apr 5, 2012.

  1. Apr 5, 2012 #1
    Johnsf

    Johnsf Bobtail Member

    7
    0
    Apr 5, 2012
    San Francisco, CA
    0
    I have a 1999 Freightliner FL70. The tach is intermittent. Sometimes it works other times it sits on zero. What is it connected to for signal? I'm assuming the power is ok since the other gauges work.
     
    Johnsf, Apr 5, 2012
    Johnsf, Apr 5, 2012
    #1
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. Apr 5, 2012 #2
    truckmechanic

    truckmechanic Medium Load Member

    534
    140
    Jan 14, 2012
    Hi Desert Ca
    0
    Which engine do you have? I would start by checking the speed sensor most likely it will be mounted on the bottom of the flywheel housing with two wires. this style the wires will rub together where they come out of the sensor. that's where I would start
     
    truckmechanic, Apr 5, 2012
    truckmechanic, Apr 5, 2012
    #2
  4. Apr 5, 2012 #3
    Johnsf

    Johnsf Bobtail Member

    7
    0
    Apr 5, 2012
    San Francisco, CA
    0
    Sorry. The engine is a CAT 3126B s/n 7AS28615.

    Is it one of the two sensors on the left front?

    [​IMG]
     
    Last edited: Apr 5, 2012
    Johnsf, Apr 5, 2012
    Johnsf, Apr 5, 2012
    #3
  5. Apr 5, 2012 #4
    truckmechanic

    truckmechanic Medium Load Member

    534
    140
    Jan 14, 2012
    Hi Desert Ca
    0
    I belive it is on the flywheel housing bit I could be wrong. I know cummins started putting there's in the gear cover on little motors in 03 or so.maybe cats the sane you can always call the dealer and have them pull the part and see which style sensor it is
     
    truckmechanic, Apr 5, 2012
    truckmechanic, Apr 5, 2012
    #4
  7. Apr 5, 2012 #5
    Johnsf

    Johnsf Bobtail Member

    7
    0
    Apr 5, 2012
    San Francisco, CA
    0
    Thanks very much Truckmechanic. I'll get under there and look tomorrow.
     
    Johnsf, Apr 5, 2012
    Johnsf, Apr 5, 2012
    #5
  8. Apr 5, 2012 #6
    bender

    bender Road Train Member

    2,105
    1,348
    Jul 20, 2010
    Don't Kid Yourself
    0
    The top sensor is the primary engine speed and signals the tach. The bottom sensor is secondary. Sensors are replaced in pairs.
     
    bender, Apr 5, 2012
    bender, Apr 5, 2012
    #6
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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