Fuel reads a little more than 1/4 ALL THE TIME.
Disconnect the leads alongside the frame rail, and the guage understandably goes to 'Full'.

Sender?????

Any suggestions on figuring this out?
If so, should I get a plastic tank with its sender?
Car parts.com lists both a '94 and a '96 in two yards, both reasonably close by. $150 for either one.
Cheaper than a dealer-supplied new sender.
Then, because the plastic tank uses an in-tank pump, how will I adapt it to work w/o it? [I have a Rochester]

Thank You,

Seth

 

There isn't much it can be.

Find the wire coming from the sender, it goes from 0-90 ohms depending on the level. If it doesn't change with the level of gas you're reading (and it's not stuck at infinite or 0) then its the sender.

 

It looks like a real p.i.a. of a job. Too bad that this car doesn't have a low-fuel light. This would permit me to hold off until spring.

The existing tank seems pristine, but the sender is so expensive.

Seth

 

If it were me: I get 250 miles a tank, every 150 I'd fill it up. Problem solved for now. Might as well check to see if its the sender and not the gauge. Takes 5 seconds once you find the wire.

 

Josh,

I did say in the initial post that when I unhooked the wire near the frame rail, the guage went to 'full'. Perhaps you did not catch this, or perhaps you wish for me to do something else at that wire connector.

Thank You,

Seth

 

Seth,
What he was referring to was to disconnect the pink wire that runs from the fuel tank to the instrument cluster and measure the resistance through it. With an empty tank the resistance value would be 0 OHM's and a full tank would register 90 OHM's. The wire that you disconnected near the frame rail was probably black/white and the ground wire. If that wire is disconnected the gage will move to the full position because the ground has been removed.

 

The frame rail connector contains both the dark and the pink wire.
Disconnect it, and I have a full tank.
Are you indicating that I may [or may not] ultimately trace this to the gauge? That would save some labor for certain.

Guess this must wait for daylight.

Thank You,

Seth

 

As Joshfirebird suggests, fill the car up. Separate the connector and measure the resistance on the sender. The reading should be 90--if so, the sender should be good. As a double-check, however, put some miles on the car to see if the reading changes as you use fuel (half tank should be about 45). Should that be the case, look at the gauge itself.

JamesC

 

With the tank topped off, the resistance between the pink and dark wire, [at the disconnected under-chassis plug], is about 93 Ohms. Traced a secondary plastic multi-plug behond the rear glove box. Funny thing is that after an unplug then re-plug, the thing showed 'full' for a bit. then went back to less than 1/2.
These plugs seem good. Am I looking at a bad gauge, where do I find one [salvage yards here are bad], and how does that pesky trip-odometer stem come out? The center screw does not budge for anything.

Thank You,

Seth

 

I recently posted questioning the weather pack near the tank and how protective it really may be. After probing both sides of the connection and thoroughly spraying it with electronic cleaner, the gauge seems normal. I'm delaying judgement, however, until I run a tank through the car.

JamesC

 

Now find where that wire attaches behind your gauge cluster and measure the resistance.

A. If behind the gauge the wire has the same resistance as the pigtail under the car then your gauge is broken.

B. If behind the gauge the has a far difference resistance than the pigtail under the car then you have a broken/damaged wire.

 

Dumb Q, but really, how do you remove that **** on the trip odometer, w/o busting things?

Great news, MUCH LESS WORK.

Seth

EDIT: Just eliminated the under-chassis plug. No difference. Will do a better splice tomorrow, or better yet, after I trace the wire to the dashboard.

 

I just pulled straight back on mine, it was an 89 though so I don't know if it changed.

 

Josh,

You mean to say that it pulls off? Is that a set screw or just decoration?

Seth

 

My trip odometer **** just pulls straight off if I remember correctly. I don't recall seeing the screw looking part you're talking about, it may have changed over the years.

 

Also, do I need to pull the instrument pod, or just remove the lens, for access to this thing?

Seth

 

I think pull everything, pod, lens, gauge cluster, etc.

 

I went out tonight. The gauge started at 1/2, then went to 3/4, then back to 1/2. When the drive began, the tank was full, and the float read 93 Ohms [across the black and pink wire, w/o the harness connected to them] . I am pretty certain/happy that the problem is in the dash.

My Q is "Is there a voltage regulator, on the instrument panel circuit board [or near it], as there is in my Dodge van?" That regulator transistor is to assure absolute stability in the gauge readings. When it craps out, the readings go wierd. I ask, because it better explains this problem, than simply a 'bad' gauge.

Am I spelling gauge wrong?
Owner's manual spells it gage. This looks incorrect. Just a thought.

Thanks,

Seth

 

while you are doing all this try cleaning ground 304 that is under the carpet just in front of the seatbelt

 

On his car that ground is behind the center trim piece in the rear cargo compartment.

 

my gauge was doing the same thing. I took the tank out 3 time. Yea lots of fun, I could go pro at that #$%$ now. so I took my cluster apart and took the clear plastic of the gauges and reinstalled my cluster. While driving I manually moved the gas gauge a few times and it started working. Try at your own risk, not responsible for any broken gas gauges.

 

The wire harness that runs trunk to driver's kick-panel has solid aluminum conductors.
I once again played with the plug in the trunk. No change. Then, I decided to pull the pink wire from the multi-plug, and simply use a wire nut instead. Now I have a gauge that works as follows:

When sender shows 17 Ohms, reading is 1/8 tank.
When sender shows 95 Ohms, gauge reads 3/4 tank, even though the tank, at that point, is quite full.
While putting 5 galons into tank from a gas can, I watched ohmmeter go up an appropriate amount.
You guys are right, when you say that it is usually the wiring or the dash gauge.
Thank you.

At least the problem is NOT IN THE FRIGGIN' TANK, knock on wood.

***********If I can get the odometer **** off**********, I intend to break into the pink wire, at the driver's kick panel.
There, I will simulate a full, as well as an empty tank, to see if it is the gauge, or if I simply need to re-center the gauge pointer.

Comments please.

Seth

 

YOU CAN DO IT!!!!!

 

Results are as follows:

Unhooked harness plug at driver's ankle.
Ohmmeter showed a full tank.
Gauge still needed to be looked at.
Pulled the gauge.
Put back, and all was fine [so I thought].
Reassembled. Problem came back in 30 seconds.
Pulled entire dash pod.
Removed clips that contact circuit board at the gauge.
Reassembled everything.
Viola' ! :

Can you kids say 'Oxidation'?

B.T.W., the odometer **** has a set-screw that required use of the screwdriver that I use to mount phono cartridges. And it is reverse thread.

Seth