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Discussion Starter · #1 ·
I replaced the Original Fuel tank, sender and gauge with the following after market pieces:
1. 20 Gal Aluminum fuel cell
2. .. included with the fuel cell was a Fuel Sender for a chevy (0-90 Ohms).
3. Autometer Fuel gauge (0-90 Ohms).
I am using the original 57 wiring that was run from the original fuel gauge to the original gas tank. I also have grounded the sender to the frame (checked the ground and it is good).
Currently with the tank half empty(just a reference on the gas level as it reads the same no matter how much fuel is in the tank), when I turn on the ignition switch the gas gauge moves from being pegged all the way below empty to just a hair below the "E".

I tested the fuel gauge as follows:
1. I took the Brown wire off of tank sender, and left it in the air not touching anything. I turned the key to on, gauge pegged to past full.

2. I then touched the Brown sender wire to frame {full ground}, turned the key on, and the gauge pegged to below empty.

So I am at my wits end on why my gas gauge will not read correctly??? Any ideas???
 

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Trifive Automotive Electrical Wiring Expert
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The gauge and wiring is good. The sender is either bad or the float is full of fuel. Is it a metal or plastic float? Does the fuel cell have foam to keep the float arm from moving up?
 

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Discussion Starter · #3 ·
The sender was alread installed in the tank when i got it from JEGS so I am not sure if it has a plastic or metal float... There is a dam around the sender in the tank so that the foam will not contact the sender. Looks like I will try and remove the sender next and test while on the bench...only question I have is how would I do that?? again its a 0-90 Ohm sender.
 

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If you have the sender on the bench, just use an ohm meter to test for 0 ohms with the sender all the way down (like the tank is empty) and then lift the arm up (like the tank is full) and you should have 90 ohms.
 

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Trifive Automotive Electrical Wiring Expert
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The sender was alread installed in the tank when i got it from JEGS so I am not sure if it has a plastic or metal float... There is a dam around the sender in the tank so that the foam will not contact the sender. Looks like I will try and remove the sender next and test while on the bench...only question I have is how would I do that?? again its a 0-90 Ohm sender.
Use a multimeter on the lowest ohm scale (usually 200 ohms). One lead on the sender terminal and the other lead on the ground connection. Move the arm up or down. You should see the meter change from near zero when the arm is all the way down to 90 ohms when all the way up.
Or you can turn the car upside down and test it in the tank. :) .....

 

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I have the same exact problem when I test mine....and my sender is new...Bah Humbug.....:sign0020:
:gba:
bowtie-trifive
 

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Discussion Starter · #7 ·
The sender in mine is also new!! I hope its Not the sender (altho its looking like it is), cause I hate buying new parts and they don't work! Guess I can take the unit out of the fuel cell and test it. I can tell you that taking it out is gonna be royal pain cause my hand is a little too big to fit in the filler hole. Hmmmmm... Maybe turning the car upside down isn't a bad idea after all... Lol
:p3:

I have the same exact problem when I test mine....and my sender is new...Bah Humbug.....:sign0020:
:gba:
bowtie-trifive
 

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How is your "fuel cell" different from a fuel tank? Does it have internal baffling (or as Don says "foam") that could interfere with float travel?
 

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You could make the measurements with the sender in the tank. Drain the tank and take a reading on the sender. It should be close to 0 ohms. Then fill the tank up, it should be close to 90 ohms.

As for as removing the sensor, it is almost as easy to drain the tank and drop the tank than remove the sensor as it is to remove/replace the sensor while the tank is still mounted.
The sender in mine is also new!! I hope its Not the sender (altho its looking like it is), cause I hate buying new parts and they don't work! Guess I can take the unit out of the fuel cell and test it. I can tell you that taking it out is gonna be royal pain cause my hand is a little too big to fit in the filler hole. Hmmmmm... Maybe turning the car upside down isn't a bad idea after all... Lol
:p3:
 

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Discussion Starter · #10 ·
I looked inside the fuel cell today and there is sort of a dam built around the float. It isolates the float from the cells foam liner. the issue is.. Because of the angle I am looking thru the filler hole, I can't see the float.. All I can see is the dam area!
How is your "fuel cell" different from a fuel tank? Does it have internal baffling (or as Don says "foam") that could interfere with float travel?
 

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If you have tried the trouble shooting guide on the guage & wiring then it would have to be the sender, the only way to be sure is to get it out and test it :anim_25:
 

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Discussion Starter · #12 ·
Update:
I got the Fuel Sender out of the Fuel Cell. It looks a lot like a stock 57 unit. Tried to test it but all I got was a grounded reading. Looks like there was a ruber type seal up top that was torn away and the rheostat was broken as well. This was a brand new Sender that I got with the tank, but it looks like an old broken one!!!! So...Years ago I had another car that had a fuel cell and came with a Chevy Fuel Sender. I needed a Mopar sender (it was going in an AMC SC/Rambler), so I replaced the Chevy Sender and put it on the Shelf for use one day!! Well 10 years, and 3 moves later it was still on my Shelf so I switched out the old broken Sender with the new (old) sender. Had to drill out some new holes for the new Sender but just went slow so as to not cause a spark and it all went back together nicely. This new Sender had a lug for the Sender Wire and the Ground Wire. I attached the Same wiring to the New Sender as I had on the Broken Sender and Walla....... She Works!!!!!! So I now have a Fuel Gauge that works!! Thanks again for all the help. I know better understand the whole Gauge, wiring, and sender relationship and how its supposed to work! Nice to know that even an old Dog can learn a new trick or two!!
So the New Gauge panel with the Auto Meter Water Temp and Auto Meter Fuel Gauge and Stock Speedometer all works. Even the Speedometer works now! Its great to have Gauges and Gauge lights that actually work! LOL
 
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