snomobeelr Posted July 29, 2015 Share Posted July 29, 2015 Fuel Gauge is stuck at Full. I pulled the fuel gauge connector in the trunk apart and grounded the brown wire going to the dash. When I turn the key on with the wire grounded to trunk the gauge goes to E-Empty. Plug it back in and goes to full? There is another connecter in the trunk with two wires - one for license plate light and I guess the other for fuel gauge. One Green and the other Brown. I have the Green wire to the green and the Brown to a Black wire? It was a new sending unit and tank. Am I going to need to pull the tank? Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted July 29, 2015 Share Posted July 29, 2015 check the ground wire from the sender on the front side of the tank to make sure its grounded Quote Link to comment Share on other sites More sharing options...
snomobeelr Posted July 29, 2015 Author Share Posted July 29, 2015 The ground wire from the sender to the front side of tank is grounded. I even sanded the spot to make sure it was metal on metal. Same thing. Quote Link to comment Share on other sites More sharing options...
Rock Posted July 29, 2015 Share Posted July 29, 2015 The guage is working properly so I would say the sending unit is bad again or it is stuck in the full position. You may have to drop it again....sucks! Quote Link to comment Share on other sites More sharing options...
snomobeelr Posted July 29, 2015 Author Share Posted July 29, 2015 Darn , It is a new tank and Sender too. Don't remember which sending unit I got. Is there a recommended sending unit I should have gotten? The Tank has the 3 vents on it. Attached a picture of the plug I was hoping I had wrong. For the License plate light and sending unit, I think ? Thanks Quote Link to comment Share on other sites More sharing options...
Rock Posted July 29, 2015 Share Posted July 29, 2015 I bought mine from this vendor..... http://www.ebay.com/itm/71-72-A-body-Fuel-Gas-Tank-Stainless-Sending-Sender-Unit-W-Return-Line-Pick-Up-/190857717771?hash=item2c7001a80b But I wonder if yours may be stuck.....I had to adjust the float on my new one to make sure it wouldnt get caught on the filler tube. Good luck. Quote Link to comment Share on other sites More sharing options...
Rboisvert86 Posted August 25, 2015 Share Posted August 25, 2015 I tried the same thing with the sender ground wire my guage is stuck a bit below the half tank marker even when the tank is full Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted August 25, 2015 Share Posted August 25, 2015 unplug the sending unit wire in the trunk and see if the gauge changes Quote Link to comment Share on other sites More sharing options...
badddoin Posted August 25, 2015 Share Posted August 25, 2015 I bought mine from Rock Auto. It's definately an el cheapo piece. I ran a wire from the battery ground and hooked the unit up before I reinstalled the tank. Then I turned the tank upside down to make sure the float wasn't getting hung up on anything. I also had to bend the float arm. Not exactly rocket science, but a real PITA. Quote Link to comment Share on other sites More sharing options...
snomobeelr Posted February 6, 2016 Author Share Posted February 6, 2016 So I found the problem with the Fuel gauge not working. It was the wire from the Trunk to the Tank sending unit. Now it works but does not register like it should..When i place the float to full it only goes to the line before the 1/2 full mark? Are there different sending units or are they all the same? See picture , that what shows when placing it to full. Quote Link to comment Share on other sites More sharing options...
snomobeelr Posted February 6, 2016 Author Share Posted February 6, 2016 forgot to add picture Quote Link to comment Share on other sites More sharing options...
Rock Posted February 6, 2016 Share Posted February 6, 2016 When I replaced my sending unit I used water in the tank and udjusted the float by bending the metal attached to the float. What I did was add 3 gallons of water and adjusted the float to read empty so I had a 3 gallon reserve. Then filled the tank and luckily it read full. As far as your unit I wonder if the float is hanging up on the add spout not allowing it to read full. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted February 6, 2016 Share Posted February 6, 2016 as Rock said...some of these sending units have the float arm bent the wrong way and the float hits the filler tube Quote Link to comment Share on other sites More sharing options...
Rock Posted February 6, 2016 Share Posted February 6, 2016 as Rock said...some of these sending units have the float arm bent the wrong way and the float hits the filler tube Yep, bend it 180 degrees so it is away from the filler tube. Quote Link to comment Share on other sites More sharing options...
snomobeelr Posted February 6, 2016 Author Share Posted February 6, 2016 I was under the car and connected the sending unit. I moved the float myself while my son watched the gauge. Quote Link to comment Share on other sites More sharing options...
Rock Posted February 6, 2016 Share Posted February 6, 2016 I posted the vendor I used and mine worked perfect. You could try a different sending unit. Question....did you have it grounded? Quote Link to comment Share on other sites More sharing options...
snomobeelr Posted February 6, 2016 Author Share Posted February 6, 2016 Yes connected it to ground. . I moved the float to the different positons while my son watched the gauge. The gauge moved as I moved the float from empty to half to full. The picture above was the full position.. Quote Link to comment Share on other sites More sharing options...
snomobeelr Posted February 6, 2016 Author Share Posted February 6, 2016 I tested the sending unit with a Multimeter...Full was 95 Ohms- Half about 46 ohms and empty was at .08 Ohms. I believe I have the same sending unit as listed above made by inline. Is it possible the Gauge itself registers at a different ohms reading? or maybe I had two issues. One was a bad wire from the tank to the trunk and maybe an issue with the gauge itself.. Quote Link to comment Share on other sites More sharing options...
Rock Posted February 6, 2016 Share Posted February 6, 2016 For the life of me I can't remember what kind of readings I got from my sending unit....I know I wrote it down somewhere. Quote Link to comment Share on other sites More sharing options...
snomobeelr Posted February 7, 2016 Author Share Posted February 7, 2016 The gauge is working properly. With the tan wire disconnected the fuel gauge reads past full with the ignition on. Touching the tan wire to ground' the gauge moves to empty so the gauge is working properly.. This means I have verified the connection from the fuel sending unit to the fuel gauge is defiantly good... Then I plugged in and tested the fuel sender again. Connecting the tan wire to the proper connection on the fuel sending unit and the ground wire to ground. I get the same results as before. With the float at the empty position the gauge reads empty. With the float in the full position, the gauge reads to the line before the 1/2 mark on the fuel gauge. But I be love the ohm reading I get on the fuel sending unit are correct.. Full was 95 Ohms- Half about 46 ohms and empty was at .08 Ohms. what the heck.. Quote Link to comment Share on other sites More sharing options...
monte70car Posted February 7, 2016 Share Posted February 7, 2016 I believe the gas gauge OHMS is 0-90, this is only base off of my aftermarket cluster and fuel cell I have in my Monte's. The sending unit when full should have 90OHMS max anything over that would case the needle to read pass full. You might be able to bend the float the arm so that the sender stop at the full mark on the gauge and be at empty with the OHMS you have provide. Quote Link to comment Share on other sites More sharing options...
Rock Posted February 7, 2016 Share Posted February 7, 2016 I believe your ohm readings are correct and the sending unit is doing what it's supposed to. What kind of resistance do you have from the trunk to the gauge? Also check for continuity between the tan wire to ground and see if it's has a slight short to ground. Other wise I am stumped. Make sure you have 12 volts at the gauge itself. The sending unit is the ground that completes the circuit so you should have no voltage at the sending unit itself. It acts as a rheostat and varies the resistance to ground. I also have to ask if you are grounding the sending unit to the frame of the car.....hate to be repedative but really important to have a good clean ground. If you can, get a wire long enough to run directly to your negative post on the battery for your ground for testing purposes. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.