Electrical Guys

Discussion in 'Employment Opportunities - Help Wanted - Skills' started by DCGallim, Jul 11, 2019.

  1. DCGallim

    DCGallim Resident Smart-A$$

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    I've got a coolant level sensor on a couple of my trucks that go bad after a month. I can get it warrantied but it's a pain to constantly change them out and the drivers having to keep a spare at all times. I'd like to get something made up that will bypass the sensor. I'm no electrical engineer and don't pretend to be one. Anyone around the Triad that can do something like this? A jumper wire doesn't work before anyone brings it up. The ohms going in are higher than going out.
     
  2. Slacker

    Slacker Liquor and Whores...

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    It's a "monitored" sensor.
    Cant bypass with a dry jumper.
    Find out what the resistor ohms are
    (10k or 7k probably) and put that in line.
    It's looking for that resistance as a normal state.
     
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  3. DCGallim

    DCGallim Resident Smart-A$$

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    That's not English to me, that's why I'd like someone to build me a few. I can wire up a rear bumper for brakes but getting into ohms and resistors is above my knowledge and current time limits to learn it.
     
  4. rdinatal

    rdinatal Better late then never...

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    Find out how to test the sensor. Usually the test says to check resistance to be 'x' ohms (good) to 'x' ohms (bad).

    Get the closest good value of a resistor and use that as a jumper. If you have the old sensors use those connectors to the existing harness.
     
    Last edited: Jul 11, 2019
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  5. Button Pusher

    Button Pusher Well-Known Member Benefactor

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    Most likely a bad connection at the connector or broken wire, see if the shop will replace the connector with new one spliced in.
     
  6. DCGallim

    DCGallim Resident Smart-A$$

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    It’s just a bad design by Mack. I’ve got 4 of these trucks and they all have the same problem. Parts guy at Mack told me Republic brings them in for warranty replacement 50 at a time.
     
  7. DCGallim

    DCGallim Resident Smart-A$$

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    Annoying design flaw, this only happens in the cab over trucks since they made the sensor different in standard trucks but they also changed the connections so I can’t rig something up that way.
     
  8. Beef15

    Beef15 B or somesuch

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    Ha, those things are garbage, most are bad, Mack's is exceptional. I broke one open a few weeks ago to see WTF? It's coolant intrusion! Ten years at least, still the same shit design.

    Our drivers can't be trusted to check their coolant so disabling is not an option I have investigated. At my old fleet back when those beautiful Cats were an option you could just turn off the low coolant shut down with ET. I could look in TechTool. I can also get you a resistance value, they have a board inside so I assume it is variable though many others are simple switches open or closed. I'll get the info, and think about producing.

    ETA: I'll try to remember this time, I dropped the ball last time I offered help.
     
    Last edited: Jul 11, 2019
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  9. Jp8819

    Jp8819 Member Benefactor Charter Life Member

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    Can you post the part number of the sensor? Also you mention diffrent trucks use a diffrent sensor can you just change the connector to one like they use that seems to last? Or are they to diffrent either electrically or mechanically.
     
  10. Beef15

    Beef15 B or somesuch

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    It's in this TSB. The new one is barely if any better.
    https://static.nhtsa.gov › tsbsPDF Web results Field Service Bulletin Trucks - NHTSA

    Looks like Dorman makes them now... Wonder if they're any better?
     
    Last edited: Jul 11, 2019
  11. DCGallim

    DCGallim Resident Smart-A$$

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  12. DCGallim

    DCGallim Resident Smart-A$$

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  13. Beef15

    Beef15 B or somesuch

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    So Tech Tool kept crashing when I tried to check parameters to see if "low coolant shutdown" could be disabled, I believe it can, out of warranty the dealer should be willing to do that, MIL will still illuminate.

    So far as a "dummy sensor" I don't currently have a pigtail, I get 6.35k ohms in the full position checking a new sensor and one in service.

    Not sure it's that simple, as I said they have a circuit board that appears molded into them, I don't know that they can be non destructively disassembled.

    If I can find a resistor and pigtail putting one together to try is easy.
     
    Last edited: Jul 11, 2019
  14. Button Pusher

    Button Pusher Well-Known Member Benefactor

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    Last edited: Jul 11, 2019