Announcement Announcement Module
Collapse
No announcement yet.
fuel gauge Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • fuel gauge

    I just installed a new fuel gauge and in tank sending unit...........i did not buy the SW unit i bought the cheaper one and it works but when you are driving the fuel gauge does not stay steady. It works correct when setting still. I have good grounds............sounds like the sending unit is bad. Anyone had this problem? IT IS A 75 cj
    Thanks
    Jack

  • #2
    Sometimes its nothing more than fuel sloshing around in the tank. If it does it when the tank is full (I mean topped off) then there maybe something in the wiring or the float settings.

    Comment


    • #3
      If I'm not mistaken the 'factory' fuel gauges had a small amount of 'grease' in them to act as dampening to prevent the gauge from fluctuating. I replaced my fuel fauge with an aftermarket unit and I don't have that problem when the tank is near empty. You might want to do some research on the OEM fuel gauge to check that it did have a dampening grease purposely placed in the gauge.

      Comment


      • #4
        Originally posted by dunlapml
        If I'm not mistaken the 'factory' fuel gauges had a small amount of 'grease' in them to act as dampening to prevent the gauge from fluctuating. I replaced my fuel fauge with an aftermarket unit and I don't have that problem when the tank is near empty. You might want to do some research on the OEM fuel gauge to check that it did have a dampening grease purposely placed in the gauge.

        No, they don't have any grease in them. The slow response time of heating a bi-metalic strip adds it's own damping factor and grease wasnt needed. OF course I'm not familiar with the gauge you bought but that is how the OEM gauges work.

        I have seen grease used in some cheap D'Arsonval movements with jeweled pivots but these mainly use coil springs for dampening also.

        Exactly which gauges did you buy?

        Comment


        • #5
          are you sure?

          John,

          I've come to regard you as one of the board's resident electrical experts but I too, had read this 'grease' thing before. Of course, the author of the below quote might be mistaken, but I thought I'd throw a tad of support Dunlapml's way. Check this out:

          "The meter movement in all the gauges have a built-in dampening mechanism which keeps the needle from bouncing around. The dampening mechanism is basically some thick grease on the movement's pivot points."

          From this link:

          http://www.jeeptech.com/electrical/gauges/

          As far as what type and where Whiteturbo should consider dabbing said grease should he decide to 'attempt' it, I'm afraid I can't help. It would seem a rather 'touchy' proposition to me. It does sound as if he's getting very little dampening effect with regard to his reading, though.
          Last edited by blackwater; 06-26-2006, 12:07 PM.

          Comment


          • #6
            Yeah I know, I use to use that site as a reference untill some stuff didn't make sense. After going through about 20 gauges without any grease in them I think he made an assumption there. Maybe they dis at one time but I never saw any in any AMC CJ's.

            I had a list of stuff that I notice were different than I discovered but not sure if it was bad form to point it out to him or not. That's why I made my own site. Even I made a couple of mistakes as carefull as I was trying to be. Sometimes I don't know what I was thinking when I wrote stuff.

            Maybe I should of been so 'final sounding' in my response, but I was in a hurry before my boss got into work. Sorry about that...

            If you ever had shorted the input on a new gauge you will see it takes a couple of seconds to reach it's final position. I think that that even sloshing around the sender moves quicker than that and you won't notice it in the gauge. However is you lose the ground and the fuel gauge stops regulating the current in the gauge, it will heat up a lot faster but not sure of the cool down rate which also effects the response time of the gauge.

            Comment


            • #7
              I wasn't disagreeing with you...

              It's all good, John. I recently had those gauges out and saw no grease, either. (Caused some questions to pop up for me as well.) I threw my two in on that because the 'misinformation' as I view it since your post is 'out there'.

              I'll keep the site errors in mind because I've used that link a lot in the past myself.

              Comment


              • #8
                Fuel gauge

                I did check my gauge and with the switch on i think it should blink and it is a solid light when i use a test light on the hot side. I talked to a parts store and they said it should blink and if it did not the regulator is bad in the gauge. I looked on this site and i think i should check the volts and ohms also before i buy a gauge. Any ideas?

                Comment


                • #9
                  Originally posted by Whiteturbo
                  I did check my gauge and with the switch on i think it should blink and it is a solid light when i use a test light on the hot side. I talked to a parts store and they said it should blink and if it did not the regulator is bad in the gauge. I looked on this site and i think i should check the volts and ohms also before i buy a gauge. Any ideas?
                  Well the "I" post should not blink. That is the power connector. The "A" or the "S" post should blink.

                  If it is not blinking then it could also be a bad ground.

                  http://users.adelphia.net/~john.stre...eQuickTest.htm

                  http://users.adelphia.net/~john.stre...for_cj_gau.htm

                  Comment


                  • #10
                    Fuel gauge

                    The s post does not light up or blink and i only have the i and s post on the new gauge. I checked it with a OHM meter and my meter reads 304.5 I am not sure what this means as i know i am looking for 19-21 from i post to s post. My meter is a fluke 77 and i am not even sure if i am reading it right....i do have it turned to the one that looks like a horseshoe. Sorry but i never used a meter very much except volts. Thanks for any help.

                    Comment


                    • #11
                      Originally posted by Whiteturbo
                      The s post does not light up or blink and i only have the i and s post on the new gauge. I checked it with a OHM meter and my meter reads 304.5 I am not sure what this means as i know i am looking for 19-21 from i post to s post. My meter is a fluke 77 and i am not even sure if i am reading it right....i do have it turned to the one that looks like a horseshoe. Sorry but i never used a meter very much except volts. Thanks for any help.
                      Sounds like your doing it right. I'm not sure how those gauges operate or the specs on them. I asked for a set when I wrote my artical but the guy told me they have a high failure rate and told me not to bother.

                      Set your meter back to Volts and with the sensor connected check the voltage on the "S" post. Let me know what you get.

                      Comment


                      • #12
                        Fuel Gauge

                        I will check the gauge this morning and get back with you. I understand that these gauges are junk after taking it apart and looking at it. Where do you get one like the OEM?

                        Comment


                        • #13
                          Fuel gauge

                          I checked the volts and the post going to the sending unit has 1.396 volts I also removed the sending unit from tank and checked ohms with my meter and it reads right. Like 10 full 23 half and mine is 75 empty..........so if the replacement gauges read lit the oem it shound be 19-21 and i am not even close to that and the test light does not light up on the sending unit post........but i would think that at 1.396 volts a 12 volt light would not light. It is looking like i new another new dash gauge and i have a company looking for the oem type with three post..........anyone know who sells the oem type gauge? The replacement one i bought does not seem like much. Does anyone known if the replacement gauge reads like the one 19-21 from the I POST TO THE S
                          Thanks
                          Jack

                          Comment


                          • #14
                            ???

                            Whiteturbo, have you taken the time to 'carefully' read John's links? That's a nice meter you have and those links are excellent. Put that Fluke to work after you study John's material. Also, 4WD hardware has replacement gauges for fuel and temperature for your year Jeep as well as temperature and fuel level sending units. (It is highly recommended that you replace both the fuel and temperature gauges as a pair.) Pull out the credit card and dial 800-333-5535. Ask for Jen.

                            Comment


                            • #15
                              Fuel Gauge

                              I know this is hard to believe but my fuel gauge works correct with the speedometer cable unhooked. As soon as the speedometer is hooked up and the vehicle is moving the fuel gauge starts to bounce and not read correct. I checked the cable to see if it was shorting with wires and did not find anything wrong. The back up lights do not work are they any wires going to the transmission that may short and cause the speedometer cable to do this. I do not drink and do not take drugs...........this really happens!!!!!!!!!!!!!!!!!!!
                              I have grounded the vehicle to death..I have a ground from the instrument cluster to the neg side of battery grounded the firewall to the same...the left motor mount is grounded and i installed a ground cable from the tub to the frame.
                              Thanks again
                              Jack

                              Comment

                              Working...
                              X