Fuel Gauge Problem

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1BadDodge71

1BadDodge71

FABO Rice Hater
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hi everyone!
I have a 72 Duster,225 Slant 6 pretty much stock and my fuel gauge dosent work.I checked it for voltage with a test light and noticed with the key on,the light on the test light blinks and then the fuel gauge starts to work but then when I take the test light off,the gauge fails to work again.So I figured the gauge actually works but must be a bad ground so I checked under the car and noticed a wire sticking out from one of the fuel lines next to the fuel tank.Is this the fuel gauge sending unit ground?If so where does it connect to because I cannot for the life of me find where it connects to.Thanks everyone.O:)
 
robs 67plymouth said:
mine just had same problem bad ground
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Im going to wait until tomorrow to mess with it.the car is outside and I was tired of being mosquito food while being under the car with a worklight,lol.Ill have to look more to see where it connects to,or maybe just make a new ground.:thumbrig:
 
Ma Mopar made a steel grounding clip that bridged the rubber hose section between the fuel tank and the fuel line to provide the ground. A lot of times people will just use a couple of small clamps and a short piece of wire to jump across the rubber fuel line piece. Without that ground the fuel sender will not normally work.
 
Steve68 said:
Ma Mopar made a steel grounding clip that bridged the rubber hose section between the fuel tank and the fuel line to provide the ground. A lot of times people will just use a couple of small clamps and a short piece of wire to jump across the rubber fuel line piece. Without that ground the fuel sender will not normally work.
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Hi Steve
Thanks,I see the ground clip,just cant find where it connects to,it looks like it came off or broke off from somewhere but I cant find where.
 
IMG_0312.jpg

Ok,heres the metal strap i was talking about.I cant find where it connects to,but even with a helper,ill touch it to the sender and the sender still will not work.The gauge only seems to work when I probe the wire(the blue wire) with my test light,but the light also blinks.Should I ground out the blue wire or will that fry the sender and gauge because that seems to be the only way the gauge will work.
 
The strap basically bridges the gap (where the rubber hose is) between the sender outlet and main line to complete the ground circuit. Make sure everything is clean so you get a good connection. If you are then convinced that you have a good ground and the gauge still doesn't work, then either the sender is bad or you have a break in the sender wire somewhere. If you ground the blue wire (briefly) and the gauge moves up to "full" then it's not in the wiring - most likely the sender.

IMG_0312.jpg
 
blah!Well,I reattached the ground strap,even tried grounding it a different way,and nothing.I grounded the wire itself,gauge went all the way to full,so the gauge works.Im thinking the sender is gone.I will mess with it again tomorrow .
 
You need to pull the wire connector off the sending and ground it for a bit while someone else looks at your gauge. It should show full deflection with the key on. If not the gauge is bad. If so (which is likely) you probably have a bad sending unit. You need to pull it out of the tank and replace it but before you do check it on your bench with an ohmmeter. It should show a low resistance which varies as you move the float. If it's open then it's bad. Sometimes you can bend the little tab connecting the wirewound resistor and you can make it work but most often not.
 
cudajim said:
You need to pull the wire connector off the sending and ground it for a bit while someone else looks at your gauge. It should show full deflection with the key on. If not the gauge is bad. If so (which is likely) you probably have a bad sending unit. You need to pull it out of the tank and replace it but before you do check it on your bench with an ohmmeter. It should show a low resistance which varies as you move the float. If it's open then it's bad. Sometimes you can bend the little tab connecting the wirewound resistor and you can make it work but most often not.
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thanks
I did ground the wire to the sending unit and my gauge did go to full,so my gauge works.I just wanted to add that before this happened when I first got the car,it had a half tank of gas(very bad stinky gas)and the gauge worked fine ,since I drained the gas,Im wondering if I dont have enough gas in the tank to give any reading(I only put like $5 worth of gas,maybe 2 gallons)Could it be possible that I dont have enough gas in the tank to give a reading?Like I said,the gauge worked very well before draning the old smelly fuel out.
 
1BadDodge71 said:
thanks
I did ground the wire to the sending unit and my gauge did go to full,so my gauge works.I just wanted to add that before this happened when I first got the car,it had a half tank of gas(very bad stinky gas)and the gauge worked fine ,since I drained the gas,Im wondering if I dont have enough gas in the tank to give any reading(I only put like $5 worth of gas,maybe 2 gallons)Could it be possible that I dont have enough gas in the tank to give a reading?Like I said,the gauge worked very well before draning the old smelly fuel out.
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The gauge needle has a home or off position and an empty position.
If the sender and gauge are both good just "switch on" should cause needle movement.
Now having said that... there is one design of sender that would collect crap in the bottom of the resistor housing. Those would hang and never show less than 1/8 tank or so, or they might not work at all until 1/8 tank.
You could crawl under and pull the sender to see which type you have, in which case you WILL need a new seal. Or just buy a sender and nip it in the bud. new senders come with a new seal.
 
If it only has 2 gallons- drop the tank, pull the sender out so you can bench test it, put a bunch of nuts in it, shake it, put it in the back of a pick up, hit every rutted dirt road you can; then clean out the inside, and seal it.
 
thanks for everyones help!I will be dropping the gas tank tomorrow and pull out the sender .Just another question,how do I remove those hose clamps?Is there a special tool needed?
 
You don't need to drop the tank if you're not going to clean it out. The sender comes out of the front. It's probably a good idea to look at it anyway to check the screen filter at the end of the pickup tube. Mine was completely gone and the tube was sucking up everything nasty floating around the tank thus it clogged up my fuel pump. I cleaned it all out since.
 
A little update for you guys.
I pulled out the sender unit and discovered the float is very corroded and had a hole in it and was filled up with gas on the inside.Im going to go ahead and test the sender with an ohm meter like was suggested.
 
Great news!I also discovered the little circuit boart that the gauge tab rubs on to measure fuel level came off.So what I did was I cleaned the contacts really good with a wire brush,found the smallest nut and bolt possible and reconnected
it.I found another float from a junked up fuel sender and cleaned the strainer,put a new seal and reconnected the ground strap and it works now!:cheers::cheers:
thanks to everyone for your help!I will replace sometime in the future but for now,it will work.
:thumbrig::thumbrig:
 
I figured I'd share that when you get one of these that's all varnished up...you guessed it...one more use for easy off oven cleaner :cheers: and for a float in a hurry the old holly side hung float thingie work's good!!

float.JPG
 
green1 said:
If it only has 2 gallons- drop the tank, pull the sender out so you can bench test it, put a bunch of nuts in it, shake it, put it in the back of a pick up, hit every rutted dirt road you can; then clean out the inside, and seal it.
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With that little bit of gas, I have even switched them out without dropping the tank! A little trickey but did it! Check to see if you can do before dropping the tank.

Also guys, thanks for this thread. I was always wondering about that broken peice of steel and what it was for!

Now why is it both our darts have this ground strap broken and both of our gauges work! Go figure!!??!!

Sorry read the thread late!
 
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