Gas Gauge just Quit.......????

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pastortom1

pastortom1

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I had a brand new fuel sending unit installed that we got from Year One about 6 months ago. Put less than 500 miles on the car.

The gauge cluster has been cleaned and reconditioned, and everything was OK, until the other day when I "floored" it briefly with a quarter tank of gas in it..............The gauge just went dead.

I tested the positive wire that plugs on the tank, with the key on.......no juice on the tester.....at all.......dead.......

What do you guys think this might be?.............Fuses are all OK, and all systems and lights are working fine...........I thought maybe a ground strap at first, BUT don't see one back at the tank.........??....Thought they all had one........this one doesn't seem to........BUT, then again, I tested the plug, and no juice with the key on.......

Any suggestions before I tear the dash out? (and my hair?) :sad:

Doc
 
My first guess would be the ground strap. Maybe something on the sending is stuck, otherwise go out and beat on your car again and maybe you will knock something loose.
 
You should have a ground strap that hooks one end to the metal outlet tube from the sending unit and the other end to the metal fuel line supplying the pump. Basically, it skips over the short segment of rubber fuel line that connects the two.

Disconnect the single wire on the sending unit's terminal. Connect an ohm meter to the terminal and ground. Depending upon how much gas is in the tank, you should get a reading. Sorry, I don't remember the range you should expect from full to empty. Someone else here can provide that info, or I've seen it posted over at slantsix.org before. The sending unit is basically a variable rheostat, providing more or less resistance with the changing level of fuel in the tank. Being a new one, I doubt the problem is there.

Sounds like you maybe lost continuity in your wire somewhere between the sending unit and the instrument cluster. Use some long wire leads to check continuity in the sending unit wire. If everything else in the cluster is working properly, it doesn't seem likely that it's a problem with the voltage limiter. As a last resort, you might need to pull the cluster to get at the guage and check it for proper function.

Good luck. I hate electrical problems.
Jerry
 
The wire that goes to the tank is not a power wire it reads ground thru the sending unit. If you ground out that wire the gauge should move, if it does not then you have a problem from there to the gauge and the sending unit is probably fine.


Chuck
 
340mopar said:
The wire that goes to the tank is not a power wire it reads ground thru the sending unit. If you ground out that wire the gauge should move, if it does not then you have a problem from there to the gauge and the sending unit is probably fine.


Chuck
Click to expand...

Chuck is right.
 
I agree with the above. Ground the sender wire, if the gauge doesnt peg. You have a problem between the wire and the gauge. If it does, you have a sender/ground issue.
 
do it at the tank sender, then take off the kick panel and find the same dark blue wire and do it again. this eliminates the possibility of the rear tail light harness having the problem( that is where the wire is loomed in). most likely you may have a gauge problem or a voltage limiter problem.
 
bumping because my gas gauge died- I hadn't driven the car in 4-5 months and now the gas gauge doesn't read properly- stays at empty. Curious what failure is most likely in this case (before I start crawling around under the car)?
Wasn't sure what failing might cause it to read full and what might cause it to read empty (as in this case)...
 
Common 12 volt test light might not show the approx' 5 volts that should be on the sender wire.
Yes there must be a chassis ground at the sender, whether factory jumper strap or otherwise. Maybe you tossed that ground strap, maybe you lost whatever was the ground path.
Maybe the fuel gauge is loose at its contact/mounting posts.
All good guesses. Let us know which was the best guess.
 
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