Ohm testing inop on meter

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  • Modis500
    Senior Member
    • Sep 2012
    • 358

    Ohm testing inop on meter

    Hi Guys,

    I was doing a misfire test on a '07 JEEP 3.7, and went to resistance test an injector. But the meter wont take a reading...asks for me to calibrate and it doesn't recognize Ch's 1&2 are hooked up. I tried different leads AND clips but no luck. Never had a meter go bad.... any help?

    Tom
    "If you aim for nothing, you'll hit it every time!"
    Zig Ziglar
  • sbreland73
    Senior Member
    • Jan 2009
    • 1076

    #2
    Originally posted by Modis500
    Hi Guys,

    I was doing a misfire test on a '07 JEEP 3.7, and went to resistance test an injector. But the meter wont take a reading...asks for me to calibrate and it doesn't recognize Ch's 1&2 are hooked up. I tried different leads AND clips but no luck. Never had a meter go bad.... any help?

    Tom
    Ohm measurements are on ch 3 & 4.

    Photo 2017-12-22 154449.jpg
    S. Breland

    Comment

    • Modis500
      Senior Member
      • Sep 2012
      • 358

      #3
      Stacey,

      Hello from a fellow Christian Bros tech. NC002 in Concord NC.
      Anyways, this is on a Modis Ultra, so its only a 2 channel scope. Still not sure why hooking it on 1&2 doesnt work

      Thanks

      Tom
      "If you aim for nothing, you'll hit it every time!"
      Zig Ziglar

      Comment

      • Witsend
        Banned
        • Nov 2012
        • 2942

        #4
        Maybe test the test leads you have with another meter and then if they are ok, you may need to shut down , remove battery and take unit apart to see if it has a fused shunt that blew.

        Comment

        • David Green
          Senior Member
          • Oct 2009
          • 382

          #5
          Originally posted by Modis500
          Hi Guys,

          I was doing a misfire test on a '07 JEEP 3.7, and went to resistance test an injector. But the meter wont take a reading...asks for me to calibrate and it doesn't recognize Ch's 1&2 are hooked up. I tried different leads AND clips but no luck. Never had a meter go bad.... any help?

          Tom
          Ohms tests are not very reliable, however unless you have an open circuit across the injector it'll probably still work. Two things spring to mind;

          1 / Could you not just unplug the injector(s) one at a time and see which cylinder does not respond to change, and

          2 / Could you not measure the current flow through each injector circuit and do a comparison!

          Comment

          • Modis500
            Senior Member
            • Sep 2012
            • 358

            #6
            David,

            I ended up doing an amperage test. The resistance test is my go-to secondary test for misfire elimination. Regardless of this, the main concern is the meter, and yes, I used different leads as stated in my original post. Just looking for insight from others who have possibly had issues with the meter on their Modis Ultra.

            Thanks
            "If you aim for nothing, you'll hit it every time!"
            Zig Ziglar

            Comment

            • sbreland73
              Senior Member
              • Jan 2009
              • 1076

              #7
              Tom, do you hear the relays clicking inside the meter when selecting ohms testing, or any meter option? If so, perhaps one tof the relays has bad contacts. If not, this may be a software issue (not initializing the scope/meter hardware).
              S. Breland

              Comment

              • Witsend
                Banned
                • Nov 2012
                • 2942

                #8
                Kinda thought or recall reading that when the Vantage ultra and Modis Ultra first came out there were complaints that Ohm graphing capability was lost.

                Comment

                • kirkbarrow.garage
                  Senior Member
                  • Jan 2015
                  • 149

                  #9
                  Originally posted by Modis500
                  Hi Guys,

                  I was doing a misfire test on a '07 JEEP 3.7, and went to resistance test an injector. But the meter wont take a reading...asks for me to calibrate and it doesn't recognize Ch's 1&2 are hooked up. I tried different leads AND clips but no luck. Never had a meter go bad.... any help?

                  Tom

                  Here's a thought, possibly not applicable in this instance though.

                  But, it is NOT advised to ' resistance check/test ' modern piezo injectors.

                  You will destroy it/them.

                  The ceramic flakes inside are fractured by the application of the wrong type or too long a connection to DC power and then ruined.

                  Hopefully nobody has done this yet

                  Comment

                  • Modis500
                    Senior Member
                    • Sep 2012
                    • 358

                    #10
                    Stacey,

                    I can hear it click once but not numerous times like when I turn on any of the other portions of the scope. I guess its a bad relay then.
                    Guess I won't be testing ohms on that machine anymore.

                    Thanks
                    "If you aim for nothing, you'll hit it every time!"
                    Zig Ziglar

                    Comment

                    • Mechatronics Engineer
                      Junior Member
                      • Jul 2017
                      • 9

                      #11
                      Originally posted by Modis500
                      Hi Guys,

                      I was doing a misfire test on a '07 JEEP 3.7, and went to resistance test an injector. But the meter wont take a reading...asks for me to calibrate and it doesn't recognize Ch's 1&2 are hooked up. I tried different leads AND clips but no luck. Never had a meter go bad.... any help?

                      Tom
                      Tom I'm not clear on your term "Hook up", do you mean you have connected to the injector before you have calibrated the ohmmeter?

                      Comment

                      • Witsend
                        Banned
                        • Nov 2012
                        • 2942

                        #12
                        I was doing a misfire test on a '07 JEEP 3.7, and went to resistance test an injector. But the meter wont take a reading...asks for me to calibrate and it doesn't recognize Ch's 1&2 are hooked up. I tried different leads AND clips but no luck. Never had a meter go bad.... any help?

                        Tom
                        Try channel one or channel two probe and touch either probe to another probe plugged into the grnd probe jack position? I think that's how basic ohm meter setup works . My $39.99 PortFreight 98674 Chinese Cent Check one has jack terminals that back light to show where to plug in probes and has a warning alarm and back light pulses if you put lead in wrong receptacle:cool
                        Last edited by Witsend; 12-27-2017, 10:20 AM.

                        Comment

                        • David Green
                          Senior Member
                          • Oct 2009
                          • 382

                          #13
                          Yes now I understand, put the probes into Ohmmeter and touch the leads probes together and zero the Ohmmeter, then it will let you continue to test components

                          Comment

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