sending unit question

G

gmarshall43

Petty Officer 1st Class
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May 5, 2002
Messages
201
My fuel gage doesn't seem to be reading properly. It won't read much higher than 3/4 of a tank when full or much lower than 1/4 of a tank when low on gas. I found a procedure to check the gage and it seems to be operating normally. The procedure tells me that the sending unit should read 30 ohms to 240 ohms for a full to empty tank. Is this standard for any sending unit? My sending unit reads 80 ohms to 168 ohms. Should I replace it? If so where is a good place to find a replacement?

Thanks,
Gary
 
Bondo

Bondo

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Re: sending unit question

Napa sells replacements.......
 
G

gmarshall43

Petty Officer 1st Class
Joined
May 5, 2002
Messages
201
Re: sending unit question

Thanks for the info. But I'm still wondering if I need to replace it with the readings I got?
 
Bondo

Bondo

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Re: sending unit question

Donno,........

Pull it from the tank,+ Test it in your hand,....... Maybe it just needs alittle Adjusting........
 
wire2

wire2

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Re: sending unit question

33 to 240 Ω is probably the resistance range the gauge is calibrated for.
(but there are other ranges)

Before pulling the sender, you can test with a potentiometer, (volume control) and an ohmmeter.

Go to any electronics store, get a 500Ω or a 1kΩ pot, ground an outside terminal and connect the sender wire to the middle terminal, (called the wiper). Turn the knob until the gauge reads "empty". Remove the sender wire connection and measure resistance from the wiper to ground. I expect you'll read ~240Ω. Connect the sender wire again, turn the pot to read "full". Measure ohms again, probably 33Ω.

If that's the case you'll need to replace the tank sender.
 
dingbat

dingbat

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Nov 20, 2001
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15,481
Re: sending unit question

If you end up replacing it take a look at these sensors. They don't bounce around like the float type sensors and they are competitively priced.

All you need to know is how deep your tank is. Measure the inside of the tank while you have the old sensor out for a look-see.

http://www.wemausa.com/specifications/ssidweb.htm
 
Texasmark

Texasmark

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Re: sending unit question

Totally agree with the answers you got. Additionally, when/if you install a new sending unit, you might want to set the float (device) so that the gauge reads empty before it hits the bottom of the tank. Will give you some emergency reserve to get home on.

Mark
 
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