I have factory console gauges and my fuel gauge reads empty even though I know it has over 5 gallons in it. I just replaced my old sending unit with one from ricks camaro. My old sending units resistor broke causing a constant full read. I checked the fuel guage with a gauge testor. The gauge functioned properly, testing from the sending unit connector.

So my question is what could cause the gauge to read empty?

Yer gonna love this, but... the terminal or wire on your new sender is grounding out, either to the locking ring on the tank (this has happened to me) or to the floor of the trunk.

Thanks I'll check those areas out.

Yeah... you have a short somewhere.

Your problem is easy... mine is tough; my gauge never reads correctly.

I have done the same as Jim...also from memory check the grounfd wire on the tank sensor is grounding.

If the ground wasnt good on the tank sensor, wouldnt the gauge read full? Thanks for all yalls feedback

The guage is looking for a ground. Since yours is on empty the guage or wire is going directly to ground. If the circuit is open ( no ground ) it will read past full.

Well Im still haveing a issue with my gas gauge. I borrowed a snapon tool that allowed me to dial in ohms connection at the sending unit. Doing this the gauge worked correctly. But when i hook it up to the sending unit it goes back to empty. Could this be a faulty sending unit? Does anyone know the GM part number for hte correct sending unit for a 68 Camaro?

Jim, did you remove the electrical sticky. I had saved this link to refrence, but cant find the info now.

Jason

http://www.camaros.net/forums/showthread.php?t=73968

$138 at GM Parts Direct for an original GM part.
$170 at NPD for an original, or $47 for after market repro at NPD.
$50 at Ricks\Ecklers
$45 at GroundUp before the Team Camaro discount. :thumbsup:

Thanks HWYSTARJOE, Im gonna go with a gm one. I just put in a ricks camaro one and doenst seem to work.

If you already tried one, and you get the same result, a "GM" unit will not fare any better.

You stated the SnapOn tool gauge made the gauge read correctly?
Was it 100 ohms or about?

With the sender inline, and gauge disconnected, what do you read with an ohm meter with the + probe on the sender wire?
With the the gauge disconnected, sender disconnected, what do you read on the sender wire?
With the the gauge disconnected, sender disconnected, what do you read on the wire from the gauge to the sender?

Chops, I forget the name of the tool, but it had a bunch of dials that allowed you to set the ohms it was "putting" out. I changed the ohms from 90 to 67 to 45 to 22 and it would make the gauge read full, 3/4, 1/2 and 1/4 like it was suppose too.

As for the readings, ill have to get back to you with that info. I went into hunting mode in October and really havent worked on the camaro any. I cant remeber off hand what the reading where. I plan on diving back into it all this evening.

If the sending unit was out of tank, as in 'on the floor', you have to hook up a jumper from s/unit chassis to car body ground to complete the circuit.

Post back your findings, the tool you used is just a simple potentiometer- as in a volume control from a radio.

Something is going low (going to ground) causing the gauge to read "E".

That could be a stuck/bent/tweaked/hung up sending unit float arm, a pinched wire from the gauge to the sender......

That's why I need to know all the separate readings

Yeah, I'm thinking you have some other issue... not the sending unit.

Using a multimeter \ ohmmeter, set it to Ohms. Connect one lead to the brown wire on the sending unit. Connect the other lead to the black ground wire on the sending unit. With the float hanging loose, the meter should read either Zero or close to 90 Ohms. Can't remember which way it reads. Move the float up and down and the meter should register between Zero and around 90 Ohms.
If it does, the sender is working properly and you have wiring issues somewhere between the tail light harness, the harness running up to the front of the car, or the dash harness. It could also be your fuel gauge.

That Snap on tool will test all the wiring and gauge if hooked up at the rear of the car. I gotta believe the problem is with the sender.:stirpot:

Jeff

I did test from the rear of the car. From the little black boot that slips over the prong on the sending unit.

I'm having the same issue. My gas gauge was working fine until I desided to replace it was a factory tachometer. I then hooked up a console gas gauge to find out that it reads just around a quarter, when I know the tank is full. I even hooked the old gas gauge back up and it still has the problem. It is starting to drive me crazy, I have checked the wiring with and ohm meter and it it seems to be good.

I have never been able to remedy my porblem either. Sorry I cant help.