Fuel gauge not working?

ROBERTG

MEMBER
2002 CHEVROLET SUBURBAN

My fuel gauge stopped working recently while I was pumping gas with the engine running(I know this is not the correct thing to do but I had my reason). Could this have caused the damage? Now the gauge reads the tank capacity for a couple of seconds when you turn on the ignition, then goes back to empty with the message center displaying low fuel? Your suggestions as to where to start would be very helpful.
Thanks Bob

10 Replies

MASTERTECHTIM

MECHANIC
4,749 POSTS

Bob it sounds like your fuel level sensor is no good. The easiest way to tell is unplug the sender unit above the tank and look at connector to see if it is melted(very common) if ok turn on key and look at gauge then jump the purple wire to the black wire and the gauge should read the opposite of what it did before, if it does we know its the fuel level sensor. Get back to me

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Sunday, March 2nd, 2008 AT 3:00 PM

DUGSWIFE

MEMBER
1 POST

RobertG,

wondering what the solution was to your problem. We just put gas in our 2002 with the engine running and now the gas gage is not working. Wondering what you found the problem to be.

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Sunday, June 27th, 2010 AT 7:42 PM

ALTOWNSEND

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5 POSTS

My fuel gauge was reading almost full, but I have about 1/4 tank of fuel. When I disconnected the fuel pump/fuel sender gray plug, and with key in the run position, the fuel gauge reads empty and the fuel pump does not activate.

With the key in the run position, with the plug off/disconnected, and jumping between the ground wire and the purple wire, the fuel gauge still remains in the empty position.

When I check resistance between the sender purple terminal and ground terminal, I do not get a reading. Am I doing this incorrectly or is it safe to presume that my fuel sending unit is bad?

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Saturday, April 15th, 2017 AT 7:29 AM

KEN L

MASTER CERTIFIED MECHANIC
42,883 POSTS

Chances are its the sender or the gauge has gone out in the cluster which is a common problem. Here is a video of the rebuilt cluster getting installed.

https://youtu.be/_HEC44xENxw

The wires go from the gauge to the main computer then out to the gauge.

Noting in between.

Please let us know what happens.

Best, Ken

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Monday, April 17th, 2017 AT 3:57 PM

ALTOWNSEND

MEMBER
5 POSTS

Okay, I found my problem. I did a swap into my 1960 C/10. I purchased a new 15/18 gallon stock GM (Blazer) fuel tank. Well, it has a six sided baffle surrounding the fuel pump/sender. The sender lever was riding on the baffle that is about 3-3/4 inches off of the floor of the tank. When I put the fuel pump in, I did not realize that this was happening.

So, I designed/engineered the float lever to go up and over the baffle. I plan to purchase some material to make the float hang from the opposite side, thus preventing it from having to reach over the baffle. Easy fix, just need to purchase material to fabricate.

Now, you may ask how I realized that the float arm was hitting to baffle. I put my ohm meter on the sender terminals to confirm that the sender was reading. Every time that I put the pump in, the meter reading went off of the chart (figuratively speaking). I finally looked down into the tank to see if there was an obstruction. There it was, only inches from where the pump housing rests; the baffle. Problem fixed. Fuel gauge working fine. It read about less than a quarter tank, which was correct. I put 6 gallons in which took it to about 3/4.

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Monday, April 17th, 2017 AT 5:05 PM

KEN L

MASTER CERTIFIED MECHANIC
42,883 POSTS

Glad you could get it fixed, those kinds of problems can be tough. Please use 2CarPros. Com anytime we are here to help

Best, Ken

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Monday, April 17th, 2017 AT 6:51 PM

BIGZ

MEMBER
21 POSTS
1998 CHEVROLET SUBURBAN
V8
4WD
AUTOMATIC
180,000 MILES

Why does my gas gauge jump from empty to full and sometimes point strait down to the temperature gauge. all the time it's bouncing around it driving me NUT'S.

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Wednesday, May 26th, 2021 AT 11:44 AM (Merged)

MMPRINCE4000

MECHANIC
8,549 POSTS

Generally it is a bad sending unit in the tank or the gauge.
Disconnect the electrical connector at the tank, gauge should point to empty. Use multimeter (Ohm setting). Most GM cars use 0-90 ohm sender, 0 would be empty and 90 would be full. If you get a steady reading at the tank sender, then it could be a defective gauge.

Another alternative is to have dealer test gauge, if gauge tests good then the sender is bad and the tank will have to be dropped, and the sender itself is not serviceable, you must replace the entire assy.