Replaced my gas tank, and now my gas gauge is doing the funky. FIXED!!!

[1969chargerrtse]

I put in a new gas tank as my original one sprung a leak after I tightened down on the clamps a little.  Being there was no pad between the tank and trunk floor, this didn't help.  Point being, my sending unit worked just fine.  It read full when the tank was full and empty when it was empty.  I simply took it from the original tank and put it in the new tank.  Now it never reads above 3/8 a tank even though I just dumped 15 gallons in it.   I grounded the tank sending unit wire and it pegged the gauge as it should.  I grounded the sending unit and filled the tank, and I get 3/8?  It worked fine before?  I pulled it out again this evening and can't find anything wrong.  When I pull it again I'll move the lever up and down and see what it reads.  It looks like a newer type as it has a plastic float.  Wa happin?

[Back N Black]

Sorry, don't have answer but man you are having bad luck with that car.I feel for ya.

[1969chargerrtse]

Sorry, don't have answer but man you are having bad luck with that car.I feel for ya.

I'm actually getting use to it, though it has been running problem free for awhile.  I'll post when I fiqure it out. Not a biggie. I can only think it's in the sending unit?  Why, you got me because it worked fine before?

[FLG]

Might be the wire 

[jaak]

Do you think the float arm could have possibly got bent while removing/replacing or while it was out of the car?

Jason

[Charger-Bodie]

Do you think the float arm could have possibly got bent while removing/replacing or while it was out of the car?

Jason

Or bent and catching on the tube?

[1969chargerrtse]

I took it out the other day to see if maybe I put it back in on an angle?  Nope, it locks in one correct position only. Anyway it was in perfect condition and the float moved freely. I'll pull it again and move the lever up and down and see what readings I get.  Tomorrow I plan on installing the Hemi mufflers, pulling the sending unit again and adjusting the rear brakes. Be back soon with answers I hope. 

[oldcarnut]

I connected all my hoses and wire today on my new tank and sending unit on this thread http://www.dodgecharger.com/forum/index.php/topic,57376.0.html
I also installed an extra ground wire.  Put in 5 gallons of gas and no movement either.  Took a long rod and manually moved the float up while in the tank and got about 3/8 on the gauge.  Connected the send wire to ground and it goes to full so I know the gauge is ok.  Please post what you find out and maybe I have the same issue only my unit is a new one but it did seem to ohm out ok. 

[1969chargerrtse]

I connected all my hoses and wire today on my new tank and sending unit on this thread http://www.dodgecharger.com/forum/index.php/topic,57376.0.html
I also installed an extra ground wire.  Put in 5 gallons of gas and no movement either.  Took a long rod and manually moved the float up while in the tank and got about 3/8 on the gauge.  Connected the send wire to ground and it goes to full so I know the gauge is ok.  Please post what you find out and maybe I have the same issue only my unit is a new one but it did seem to ohm out ok. 

I got bad news for us. I have no idea???

I pulled the unit out and attached the gauge wire and then a ground wire to the unit.  It worked 100% perfect.   It was full at full , and 1/2 a tank at mid point, and empty at full closed?

I have no idea?  I put it back in my tank that is half full and it reads EMPTY!  WTF?  I'll ask the Mopar pros at my cruise night tonight and post again.

Thank God it's not just me.

I hope it's not the tank?  I wish I could see in there but I can't with it mounted.

[FLG]

Is the float cracked and filling with gas??

[Brock Samson]

these things are ALLWAYS trouble,.. I've gone thru my R/Ts three times and it never has worked properly,.. one in a blue moon it will register and none too accurate at that,.. I'm gonna say 5% of the time and I don't trust it then...
I'd like to hear the experts advise and experiance in getting the blasted guage to work properly...

[1969chargerrtse]

Is the float cracked and filling with gas??

I was wondering that as there is a tiny amount of gas in it, very small amount.  but when I pull it out,  as seen in the picture there was nothing in it except that tiny amount.  It also worked fine in the old tank.  I did try to find a leak or crack and didn't see any.

[oldcarnut]

I got bad news for us. I have no idea???
I hope it's not the tank?  I wish I could see in there but I can't with it mounted.

I was able to take a small bright flashlight and take a look inside mine as I moved the float up with the rod but I didn't see anything obvious.  I put exactly 5 gallons in it. I don't have any more time today but later this week I'll pull it out and move the float lever out of the tank like you did and see if the results are the same as yours.  Then I'll put it in a containor of gas and see if that makes any difference. Hopefully the pros have an answer. 

[y3chargerrt]

Rob if your gauge works fine when you have your sending unit out and moving it by hand then your float has to be the problem.It must has gas in it keeping it from raising.

http://cgi.ebay.com/ebaymotors/MOPAR-Sending-Unit-Fuel-Tank-Brass-Float-Dodge-Plymouth_W0QQcmdZViewItemQQ_trkparmsZ65Q3a1Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp4506Q2ec0Q2em245QQhashZitem35a1947678QQitemZ230344128120QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessoriesQQsalenotsupported

[1969chargerrtse]

Rob if your gauge works fine when you have your sending unit out and moving it by hand then your float has to be the problem.It must has gas in it keeping it from raising.

http://cgi.ebay.com/ebaymotors/MOPAR-Sending-Unit-Fuel-Tank-Brass-Float-Dodge-Plymouth_W0QQcmdZViewItemQQ_trkparmsZ65Q3a1Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp4506Q2ec0Q2em245QQhashZitem35a1947678QQitemZ230344128120QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessoriesQQsalenotsupported

Thing is it worked before?  Thanks for the great link.  Being it did have some fuel in it I'll buy the brass one you listed.  I'm thinking something to do with the ground?  I'm going to try grounding the fuel line elbow that comes out of the unit.

[1969chargerrtse]

Well, I just crawled under the car and put a jumper from the tank to the gauge wire.  My son sitting in the car said the gauge pegged full.
I then put the wire on the sending unit stud and and grounded the unit and he said the gauge dropped to empty,
I guess it's the float? Because I know the unit works correct as I checked it outside the car today.  I guess the small amount of fuel I saw in it is making it sink.
Why it worked perfect until I moved it to the new tank is beyond me.
We shall see.  Thanks for the link y3chargerrt

[1969chargerrtse]

THIS IS UNREAL.  I replaced the float, nope that ain't it.   I went and filled the tank full and look at the reading.  I grounded the sending unit to the ground to the trunk lamp and to the frame, nope that ain't it.    I grounded the sending unit wire and the gauge went to full so that system works.  I grounded the sending unit out of the car and moved the lever and it worked 100% perfect?   This really really boggles me.   I do this type of trouble shooting for a living and I can't figure it out.  I'm sure the tank is an empty shell, what would be stopping the lever from rising?  It worked before in the old tank? I don't get it?    I will figure this out, but I don't get it? 

I thought " maybe "  the small amount of fuel in the plastic float might be the issue.  Nope.

Now I have to wait until I burn out the full tank of fuel so I can pull the sending unit again.

You would think this car is driving me nuts and making me old.  The opposite, this car is a loving and fun challenge and brought me back to life.  ( Yes I'm serious ).

[1969chargerrtse]

I have an idea?  What if the hole for the sending unit is angled incorrect?  Meaning the gauge unit and pick up is really lets say 4 or 6 inches above the bottom of the tank?  Therefore not only reading wrong but the float is topped out to the top of the tank?  I don't remember it looking that way each time I installed the unit but    when I clamp it down maybe it angles upward?  I think I have something here. 

Probably not it, but if it was I could just bend the tube and pickup downward.

[1969chargerrtse]

I just talked to somone today that said they do bike tanks and that Is a common problem when changing tanks. They do bend and reset the old sending unit to the correct position in the new tank. Of course it's been raining here in Ct for days and will be for several more days so I'll have to wait before I can drive the gas level down. Be back soon.

[oldcarnut]

I hope that works for ya. I could only get mine to read a little over 3/4 tank connected outside the car.  This weekend I'll swap it around with my R/T unit and see if it is any difference.

[roger01]

yes you do have to bend the tube for it to read properly .it took me three tries and finally got it right .
mine was reading 1/4 tank when full when i first put it in ....now reads 7/8 full when full , good enough for me ..

[1969chargerrtse]

Finally fixed!!!!!!!!!!!!!!!!!!!!!   The trick was not bending the tube, but bending the float arm so it doesn't have to travel as high. 

I did bend the tube, but I had to bend it back as it wouldn't mount up correct, so I did a little float rod bend and wammo!!!!!!!

All gauges are working fine.   

[1969chargerrtse]

What I did was use a garden hose and drain the full tank into a bunch of gas cans so I could pull the sending unit again.

[Brightyellow69rtse]

ive had my car 9 years and ive never had  a working gas guage lol. i think its time i just order a new sending unit

[1969chargerrtse]

ive had my car 9 years and ive never had  a working gas guage lol. i think its time i just order a new sending unit

If you ground your gauge wire that snaps on the sending unit to ground and the gas gauge pegs full then yes it would be the sending unit that is bad or not adjusted correct.
My issue was the gauge worked before I changed the tank, why not now?  The thing was driving me nuts.  Could you tell? 

[oldcarnut]

Finally fixed!!!!!!!!!!!!!!!!!!!!!   The trick was not bending the tube, but bending the float arm so it doesn't have to travel as high. 

If you bent the arm so the float wouldn't travel as high, wouldn't that make your gauge read even less.  I thought I read it at first that you bent it so the float would raise higher indicating a fuller tank but I wanted to make sure.  I tried bending mine down (a lot) to make it raise higher but it still didn't regester full.  I took apart the unit to check the copper strip inside but didn't help much either.  Seems like the arm has to be in the upper range of the swing on mine to start reading gas and not enough to bend to get it there floating wise.  I'm fed up with wasting time on it  and going to order another one but this time locally so I can at least return it and get some money back if it don't work. The one I got is a loss of $60. Only brand I can run across anyone selling is Spectra.  I'm glad you at least got your's fixed 

[1969chargerrtse]

Finally fixed!!!!!!!!!!!!!!!!!!!!!   The trick was not bending the tube, but bending the float arm so it doesn't have to travel as high. 

If you bent the arm so the float wouldn't travel as high, wouldn't that make your gauge read even less.  I thought I read it at first that you bent it so the float would raise higher indicating a fuller tank but I wanted to make sure.  I tried bending mine down (a lot) to make it raise higher but it still didn't regester full.  I took apart the unit to check the copper strip inside but didn't help much either.  Seems like the arm has to be in the upper range of the swing on mine to start reading gas and not enough to bend to get it there floating wise.  I'm fed up with wasting time on it  and going to order another one but this time locally so I can at least return it and get some money back if it don't work. The one I got is a loss of $60. Only brand I can run across anyone selling is Spectra.  I'm glad you at least got your's fixed 

Here's the deal.  My gauge worked perfect before the tank swap.  My gauge worked perfect in my hand with a ground wire on the base of it and the gauge wire connected, so why won't it read full in the tank was my issue?  I was frustrated putting it in and out.  Finally I sat there on my garage floor with the thing in my hand just staring at it.  I knew if the float "could " float up it would read full.  What is stopping it? It has to be hitting the top of the tank.  So I bent the rod a little in a downward angle to lower the float height, meaning the float will still make a full swing but it will now clear the tank top height instead of hitting it.  Kinda like it shortened the swing travel length, but still allowed it to go from empty to full but in a shorter path.  Do no give up!  Do not let the car beat you.  You are human, it is metal, you must win. 

[Highbanked Hauler]

  Things don't change NOW my 69 is giving me fits and I wanted to pull this thread out of the vault,  With an empty tank I am at the gauge goes to full instantly so the hunt is on. More to follow.