Gas Gauges, Can't Live with them, Can't Live without them......

[wally426ci]

So, I thought Id try a seperate thread here and try and get some input. Last weekend I bent the float rod with no results. I'm kinda wondering if its the gauge too.. I did not do the logical thing of raising it, lowering it, checking the gauge each time. That may be my 1st step since my last steps were backwards.  I won't get a chance for a little while to work on it b/c its 30* outside and I'm in the middle of a house project. 

This is the 3rd sending unit in the car, 2nd new one. 

Any other ideas? 

[the_engineers]

Does the gas gauge move at all?  You can test that by BRIEFLY touching a 12 Volt lead to it (no more than a second).

[GoodysGotaCuda]

I believe it works, but isn't calibrated correctly..

[MEK-Dangerfield]

Let's eliminate the gas gauge by grounding the blue wire that goes to the sending unit. When you turn your key to the "on" position, the gauge should read past full. If so, then it's your sending unit.

[wally426ci]

Such genius' on this site... 


Goody's right, the gauge will go almost full on fill up, then drop to below half on less than 50miles.... 

[GoodysGotaCuda]

Let's eliminate the gas gauge by grounding the blue wire that goes to the sending unit. When you turn your key to the "on" position, the gauge should read past full. If so, then it's your sending unit.

Just don't do that for long, the gauge is designed to have some resistance value in the circuit. Could potentially hurt the gauge if you left the key on with a grounded sender wire.

Wally, where did you buy your sender?

[wally426ci]

I cant remember the name. They're spot was right next to mine @ Carlisle somewhere around L124....... 

[sleepychallenger]

just dont drive more than 50 miles 

mine does the same thing, it is from year one. would love to get it working right. i even mailed off the gague to have it rebuilt thinking that was the problem. never thought to ask here

Drew

[quagmire]

Mine also does the same thing, I know my car's bad on gas but not that bad.  I can drive like 15-20 miles and it'll be down to half a tank.  When it is on "E" I still usually have at least 1/2 left.  I have a brand new sender properly grounded and the correct Autometer gauge for Chrysler senders.  It seems to be a big problem with the aftermarket senders.  My guess is the potentiometer strip where the wiper sweeps across isn't right because my float travel is the same as my original was. 

[MEK-Dangerfield]

My guess here....


 If you have an after-market sending unit, it would be interesting to have an ohm meter on it as the float travels from full to empty. Maybe there isn't a linear movement with them?  That makes them kinda useless, doesn't it?   


  Mike

[quagmire]

Yeah, I'm willing to bet that's the problem.  My old one rotted and I never bothered hooking it up to a scope to sweep it.

[wally426ci]

Maybe I need a good used one.......

[cudaneil]

  Hello wally,Im new here but i have been told that the stainless grounding strap that clips onto the fuel pipes near to the tank,causes a lot of trouble with the guage not working

                  properly in these cars if not clean and making a good contact.................hope this helps !

                                                                                   cheers Cudaneil.      

[wally426ci]

Thanks Neil, I actually ran my own ground wire hose clamped to the tube & I squeezed it between the shipping bracket & the frame..... 

[Chryco Psycho]

I have seen a lot of this , the windings on the contact strip must noe be properly spaced causing uneven readings as the float drops