71SSclone Posted July 10, 2021 Share Posted July 10, 2021 Hi everyone, I'm trying to trouble shoot my fuel gauge on my 71 Monte. Fuel gauge always reads empty. From the trunk, I can access the single wire connector that goes to above the fuel tank. I unplugged the connector. Using an ohm meter, it reads 96 ohms with the key on, and 1.3 ohms with the key off. Measuring voltage on the harness side, it reads 8.5 volts with the key on, 0 volts with the key off. I think I have excess resistance in the tan fuel gauge signal wire. Has anyone measured voltage on the tan signal wire at the trunk? Shouldn't it be 12 volts? The first few times I unplugged the tan signal wire in the trunk, the fuel gauge didn't move, but now when I unplug the tan signal wire, the fuel gauge goes to past full to around the 3:)0 position. Thoughts? John Quote Link to comment Share on other sites More sharing options...
71SSclone Posted July 10, 2021 Author Share Posted July 10, 2021 Quote Link to comment Share on other sites More sharing options...
71SSclone Posted July 10, 2021 Author Share Posted July 10, 2021 Also, does anyone have pics of how their fuel tank is mounted? This is how mine is, and it sure doesn't seem correct. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted July 10, 2021 Share Posted July 10, 2021 No it won't have 12 volts to it. If you put 12 volts to it you will fry the sending unit (ask me how I know) you should check the ground wire first. The straps look like they have been replaced with something other than original type. Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 10, 2021 Share Posted July 10, 2021 To add to Steve’s comment. It could possibly be the incorrect tank also. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted July 11, 2021 Share Posted July 11, 2021 Heres the front and rear attachment spots, in the one you can also see the ground wire attached to body. As far as I know these are still all original bolts except for what I replaced. Also as far as I know it's the original tank too, it looks and fits as it should. Also still has original lines too. Some of the pictures will not load I'll try again. 1 Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted July 11, 2021 Share Posted July 11, 2021 The straps on your tank, 71SSCLONE are correct. The small hole, facing the bumper is supposed to have a self tapping bolt going threw it into the shorter part. Then bend the strap slightly at the back of the tank. Tighten the long bolts near the rear differential till the straps are tight against the tank. As far as your gauge, it should read full unplugged. Check the ground wire for connection and good ground. If that is good it is the rehastat. Basically the sending unit is no good. 1 Quote Link to comment Share on other sites More sharing options...
Brew Posted July 11, 2021 Share Posted July 11, 2021 Agree with Mc180 ground or unit bad Quote Link to comment Share on other sites More sharing options...
71SSclone Posted July 11, 2021 Author Share Posted July 11, 2021 Thanks for the help and thanks for posting pics. I'll dig into it more today. I definitely did not see a ground wire attached to the body, so I'll check there first. Looks like I need to drop the tank anyways to check for a fuel leak. I'll get new bolts with a longer threaded part to draw the straps tight and install the 2 bolts in the rear of the straps. The tank and straps were replaced recently, but I'm not sure about the sending unit. Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 11, 2021 Share Posted July 11, 2021 If you are wanting the correct bolts,you can order them from The Parts Place. Not expensive Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted July 11, 2021 Share Posted July 11, 2021 I actually have to drop the tank back out of mine and bend the arm on the float because mine dosen't read accurately, it'll be the 4th time I'll be dropping it out gotta run the gas down so it's not so heavy Quote Link to comment Share on other sites More sharing options...
71SSclone Posted July 12, 2021 Author Share Posted July 12, 2021 Dennis- thanks for the tip. Just ordered new tank hardware. Couldn't work on it today due to rain. Quote Link to comment Share on other sites More sharing options...
71SSclone Posted July 29, 2021 Author Share Posted July 29, 2021 Update, fuel gauge is fixed and the tanks is now mounted correctly. Looks like the ground wire from the sending unit was connected directly to the fuel gauge sending wire. Repaired the wiring, installed new fuel lines, and reinstalled the fuel tank with new hardware from the Parts Place. 1 Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted July 29, 2021 Share Posted July 29, 2021 Glad you got it fixed!! Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 30, 2021 Share Posted July 30, 2021 Good job. What’s next? Quote Link to comment Share on other sites More sharing options...
Brew Posted July 30, 2021 Share Posted July 30, 2021 Awesome! Good job! Quote Link to comment Share on other sites More sharing options...
71SSclone Posted July 30, 2021 Author Share Posted July 30, 2021 1 hour ago, Dtret said: Good job. What’s next? Check in the engine section. Gotta replace the flexplate. lol I also have new front lower control arms and coil springs to install. I've already replaced the front upper control arms Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 30, 2021 Share Posted July 30, 2021 9 hours ago, 71SSclone said: Check in the engine section. Gotta replace the flexplate. lol I also have new front lower control arms and coil springs to install. I've already replaced the front upper control arms Yep I seen that. That should take about 25 minutes to do. JK. lol. Quote Link to comment Share on other sites More sharing options...
willie Posted July 30, 2021 Share Posted July 30, 2021 Nice going John. Keep on going!!! Dennis LOL 25 min, lol. Takes me 25 min to start mine. I walk around her for 20 and 5 min to start her. LOL Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 30, 2021 Share Posted July 30, 2021 6 hours ago, willie said: Nice going John. Keep on going!!! Dennis LOL 25 min, lol. Takes me 25 min to start mine. I walk around her for 20 and 5 min to start her. LOL Ya it takes me 25 minutes of debating on whether I even want to drive my cars. Cause if I do then I get to spend weeks fixing them. That’s why I never drive them. Lol. Quote Link to comment Share on other sites More sharing options...
willie Posted July 31, 2021 Share Posted July 31, 2021 Ya it takes me 25 minutes of debating on whether I even want to drive my cars. Cause if I do then I get to spend weeks fixing them. That’s why I never drive them. Lol Dennis i feel your pain. I just dont want to clean them again, and again. Seems like an hour drive cost you 8 to 10 hrs cleaning time. Thats why i should build myself a driver. LOL Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 31, 2021 Share Posted July 31, 2021 1 hour ago, willie said: Ya it takes me 25 minutes of debating on whether I even want to drive my cars. Cause if I do then I get to spend weeks fixing them. That’s why I never drive them. Lol Dennis i feel your pain. I just dont want to clean them again, and again. Seems like an hour drive cost you 8 to 10 hrs cleaning time. Thats why i should build myself a driver. LOL My 88 is that nice but not my chevelle. But I don’t clean them much anyway. Drivers not show cars. Quote Link to comment Share on other sites More sharing options...
71SSclone Posted August 2, 2021 Author Share Posted August 2, 2021 Drivers are the way to go. I'm way too picky if I had a show car Quote Link to comment Share on other sites More sharing options...
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