1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
  2. ALL NEW MEMBERS READ THIS FIRST!! Thank you for joining Heavy Equipment Forums! If you are new to forums we communicate with "Threads", please search our threads to see if your topic may have already been answered and if not then click "Post New Thread" in the appropriate forum. This will allow all of our members to see your question and give you the best chance to be answered. After you've made a number of posts you will graduate to Full Member status where you'll see a few more privileges. Following these guidelines will help make this the best resource for heavy equipment on the net. Thanks for joining us and I hope you enjoy your stay!!

White-GMC 94’ STC 330 N14

Discussion in 'Trucks' started by Spud_Monkey, Apr 21, 2020.

  1. crane operator

    crane operator Senior Member

    Joined:
    Mar 27, 2009
    Messages:
    4,813
    Location:
    sw missouri
    The back of your speedometer should have a series/ row of switches. 7-9 or so. You can toggle them each way to vary for different rear ratios.

    I've included a couple charts that I found images of. Your going to need to find out who made your gauges and hopefully a chart like I posted that corresponds to your gauges.

    I switched rear ratio's on my western star and I never messed with the speedometer. I just know that I'm not going as fast as the speedo reads. Its got 411's so I can't run very hard anyways.

    [​IMG]

    [​IMG]


    [​IMG][​IMG]
     
    Spud_Monkey and DMiller like this.
  2. DMiller

    DMiller Senior Member

    Joined:
    Feb 22, 2010
    Messages:
    9,132
    Occupation:
    Retired
    Location:
    Hermann, Missouri
    Dipole or Dip switches
     
    Spud_Monkey likes this.
  3. farmerlund

    farmerlund Senior Member

    Joined:
    Nov 23, 2014
    Messages:
    732
    Occupation:
    Farmer/ excavator
    Location:
    North Dakota
    These guys are pretty good with speedometers and other things in the dash.

    Precision instrument 602-973-1055 they are in AZ
     
    DMiller and Spud_Monkey like this.
  4. Truck Shop

    Truck Shop Senior Member

    Joined:
    Dec 8, 2015
    Messages:
    5,193
    Occupation:
    fry cook
    Location:
    SE Washington St
    Unless you have a matching calibration table for the speedo head the combinations are endless. And even with a calibration chart it can be off so then comes the fine tuning.
    That's why I installed a GPS speedometer in the Mack, there is some lag but not much.

    What I bought.

    s-l1600.jpg
     
    Last edited: Nov 21, 2020
    DMiller and Spud_Monkey like this.
  5. Spud_Monkey

    Spud_Monkey Senior Member

    Joined:
    Sep 15, 2018
    Messages:
    1,690
    Occupation:
    Retired Combat Vet Mechanic/Welder
    Location:
    46.044135 -106.160555
    I'm going with Autometer as I have in the past and is in the current RV rig I have. There is no Dipole or DIP (Dual in-line package) switches and no speedometer cable to change out. Called across the US to Volvo dealerships and ran across a fellow who said it's a gear in the back of the instrument cluster housing part number 9999-0006 and there is multiple variations that he said I would never find the right one cause they don't correspond to any ratio that he could find plus no longer made. So looks like cut gauges out put sheet of black colored aluminum over it with two holes and wire in a RPM and matching GPS speedometer.
     
    DMiller, colson04 and Truck Shop like this.
  6. Truck Shop

    Truck Shop Senior Member

    Joined:
    Dec 8, 2015
    Messages:
    5,193
    Occupation:
    fry cook
    Location:
    SE Washington St
    Good idea! It's why I went that direction way less crap, about as simple as it gets. And running steady it's real accurate. I used a KW electronic tack which that kept it simple plus it was free.:p
    The less wires in a vehicle the better.
     
    DMiller and Spud_Monkey like this.
  7. Spud_Monkey

    Spud_Monkey Senior Member

    Joined:
    Sep 15, 2018
    Messages:
    1,690
    Occupation:
    Retired Combat Vet Mechanic/Welder
    Location:
    46.044135 -106.160555
    Plus I get a 15% military discount there :p
     
    DMiller likes this.
  8. DMiller

    DMiller Senior Member

    Joined:
    Feb 22, 2010
    Messages:
    9,132
    Occupation:
    Retired
    Location:
    Hermann, Missouri
    Now I remember
    Stepper motor system, were not worth a crap back in the day
    Changes frequency to the signal for the other variables
    Stupid design yet again

    Better off with GPS
     
    Spud_Monkey likes this.
  9. farmerlund

    farmerlund Senior Member

    Joined:
    Nov 23, 2014
    Messages:
    732
    Occupation:
    Farmer/ excavator
    Location:
    North Dakota
    That's pretty cool. I didn't know they even had GPS ones. I should get out more.:D
     
    Spud_Monkey, DMiller and Theweldor like this.
  10. DB2

    DB2 Senior Member

    Joined:
    Jan 4, 2015
    Messages:
    551
    Location:
    Winnipeg MB Canada
    Farmerlund you can even get a speedometer app for your phone.
     
  11. colson04

    colson04 Senior Member

    Joined:
    Apr 11, 2016
    Messages:
    833
    Location:
    Delton, Michigan
    I use one on my phone every time I drive a vehicle for the first couple times. Never know if the speedometer is accurate, and I don't need any unnecessary traffic stops for something so easy to verify with today's portable technology.
     
    Spud_Monkey, DMiller and DB2 like this.
  12. farmerlund

    farmerlund Senior Member

    Joined:
    Nov 23, 2014
    Messages:
    732
    Occupation:
    Farmer/ excavator
    Location:
    North Dakota
    I just used the phone one the other day. Got my old 68 f 100 out and running. the speedo is off cuz i changed replaced the 3 speed years ago. looks like its fast by 8 mph.
     
    DMiller and DB2 like this.
  13. seatwarmer

    seatwarmer Senior Member

    Joined:
    Mar 13, 2013
    Messages:
    485
    Occupation:
    Enterprise Engineer
    Location:
    South Africa
    How legal is it to use a GPS speedo in the US ?
     
    Spud_Monkey and DMiller like this.
  14. DMiller

    DMiller Senior Member

    Joined:
    Feb 22, 2010
    Messages:
    9,132
    Occupation:
    Retired
    Location:
    Hermann, Missouri
    Speedometer is a speedometer, so long as registers within a percentage of accuracy no one cares.
     
    Spud_Monkey likes this.
  15. mitch504

    mitch504 Senior Member

    Joined:
    Feb 27, 2010
    Messages:
    5,213
    Location:
    Andrews SC
    Speedometer should be off by a percentage, not a number.
     
  16. crane operator

    crane operator Senior Member

    Joined:
    Mar 27, 2009
    Messages:
    4,813
    Location:
    sw missouri
    He's probably somewhere between 15 and 58mph. :D Its a 3 speed in a 68 f100- I doubt he's hitting 80.

    Do they even have speed traps in N. Dakota?
     
    DMiller likes this.
  17. Spud_Monkey

    Spud_Monkey Senior Member

    Joined:
    Sep 15, 2018
    Messages:
    1,690
    Occupation:
    Retired Combat Vet Mechanic/Welder
    Location:
    46.044135 -106.160555
    Yeah they do, seen a few driving through, rare site. Next time I should take a picture of it for keepsake :p They even have them in Montana on the east side, you would think 80 mph would be enough.... nope. I laugh when I see those pulled over, they deserve it for doing 86 plus mph.
     
    dust eater and DMiller like this.
  18. DMiller

    DMiller Senior Member

    Joined:
    Feb 22, 2010
    Messages:
    9,132
    Occupation:
    Retired
    Location:
    Hermann, Missouri
    Left UT in 1980 returning to MO, International Scout II with a 16' tandem Uhaul behind it. Running the old 345 as hard as I dare across WY was doing right at 80 at 11pm running I80. See car coming up pretty quick comes up alongside me turns on his Dome Light, STATE COP!!! I turn mine on, he waves, I wave back, he speeds off into the night. I am told it is STILL like that!! Just make certain the drivers are awake and attentive.
     
    Spud_Monkey likes this.
  19. Truck Shop

    Truck Shop Senior Member

    Joined:
    Dec 8, 2015
    Messages:
    5,193
    Occupation:
    fry cook
    Location:
    SE Washington St
    I drove my Pete for years without a working speedometer, ran four states and Canada never had a moving violation. As a mater of fact I've never had a moving violation, only one
    log book citation and that was minor.
     
    Spud_Monkey likes this.
  20. Tenwheeler

    Tenwheeler Senior Member

    Joined:
    Dec 16, 2016
    Messages:
    647
    Location:
    Georgia
    I do not thank a speedometer is a requirement. Also do not thank a windshield is a requirement. Just have to have windshield wipers.
    So goggles, no windshield, windshield wipers and you are good until you cross the next state line and have new rules.
    How does it work in S A? I am sure by the seat of your pants is fine?
     
    Spud_Monkey and Truck Shop like this.