I had to have a leaking gas tank on my '95 XL replaced, as well as the fuel pump/ fuel gauge sending unit.

When I got it back I noticed the gas gauge needle stayed where it was (about 3/8 of a tank) after stopping and removing the key.

I hardly ever drive it and these days my memory really sucks, so I'm not sure if it was like that before; I don't think it was.

In case the gauge itself was stuck I filled the 17 gallon tank; it took 6 1/2 gal.

The gauge went to a needle's with below full (not past full like most).

Is it normal gauge behavior to not read all the way full, and to read roughly 1/3 of a tank but only need about 1/3 of a tank to fill up?

 

No it is not. I would question the fuel pump install

 

The way your gauge is reading with the ignition on is not normal. However, the gauge still staying in place when shut off is normal. At least mine does. I can't say it is still reading correctly with the ignition off though. It just does not go all the way to the bottom like the oil pressure, temperature or battery does. It is not staying on, I think it kind of just stays near where it was when shut off.

 

Thanks for the responses.

> No it is not.

> However, the gauge still staying in place when shut off is normal.

Hmm, guess I need a tiebreaker.

 

Fuel gauge on Ranger may or may not change with key off, it will NEVER drop down to Empty with key off
If the actual fuel level is near Empty, when you turn the key off gauge will actually go up a bit, lol

1989 and up Rangers use sender and gauge using these OHMS
Empty 16 ohms
Full 160 ohms

And like most gas gauges its not linear, because its using and arm with a Float at the end, lol, so it may show 3/4 tank or 1/4 tank for awhile longer than when going from 3/4 to 1/4

And Rangers, along with most others, have an anti-slosh circuit on the gauge, this prevents the needle from going up and down every time you go around a corner and the float goes up and down as the gas in the tank "sloshes" around
Rangers(most Fords) have a separate anti-slosh module on the back of the cluster which is known to fail, causes gauge to read Empty all the time or Full all the time, not hard to swap out but you do need to pull the cluster out

 

Very informative, thanks Ron.

One last thing - is current flowing and draining the battery to keep maintain the gauge reading?

 

No

The only things on with key off are
Computers KAM, keep alive memory
Radio's clock and preset memory
These draw about 0.02amps, 20mA

Other things that can be on in a 1995 with key off
GEM module, but only for 30min after key off
Factory alarm, needs to be "watching" lol
Keyless entry(fobs), needs to be "listening" for Fobs radio signal

 

Great, thanks again!

 

So what holds the needle in position?

 

Ford used to use bimetalic "spring"/coil that would heat up when it has 12v and a Ground thru the sender, OHMs from sender changes the "heating" of the coil/spring
This is for analog gauges of course

Very simplified diagram here: https://encrypted-tbn0.gstatic.com/i...85uKw&usqp=CAU
"Transmitter" is the sender
So with key off/12v off, the needle drops to where ever spring/coil holds it, usually just above empty but below 1/4

Your fan clutch use bimetalic, so does your turn and 4-way Flasher, and air pre-heater, if its stock


Chevy used electromagnet type I believe, diagram here: https://constructionmanuals.tpub.com...14273_82_2.jpg

 

Ron,

Now I'm a bit confused.

My gauge is staying on Full, so either it isn't the type you just described, or something's wrong with it.

 

Yes, something is wrong with it

 

OK, so now I'm clear on that.

Do you know if it pulls significantly more current to keep the gauge reading Full?

Because after sitting for 3 days I just got a click when when I tried to start it; I very rarely have a full tank.

Bizarrely, I was only going to drive it because my car's battery was completely drained (no instrument panel lights even) after sitting for 4 days.

 

In Cab fuse box, pull out Fuse 25(10amp) see if fuel gauge changes, key off

Fuse 25 powers powers a few things but only speedo in the cluster and has full time 12volts, not a key on circuit, so shouldn't effect fuel gauge, but...............something is wrong so give it a try

Cab Fuses 11 and 15 also power cluster but should be Key on power not 24/7, you could pull them just to see


And just a heads up
Battery's can SELF DRAIN, very common at end of life
After battery has not been charged for a few hours test its voltage, i.e. after engine has been off a few hours

A new battery will show 12.8volts
12.5volts is a 3 year old battery
12.3volts is a 5/6 year old battery and time to shop for battery sales, end of life is near

12.2volt or lower is a drained or failed battery

You can disconnect 1 battery cable and then test battery volts, WRITE IT DOWN
Then come back in a few hours or next day and retest volts, should be EXACTLY the same
If its lower then battery is self draining, has a short in one of the cells, as said very common for battery to fail in this manner, even a new battery can do this
The plates inside these batteries are very close together, its how they store and release voltage, if one plate has some debris or a slight warp then it can touch adjacent plate, which causes electricity to flow and it will start to SELF DRAIN

So if you have a dead/low battery after it sits for a few days then this is the FIRST thing to test
Then you can move on to alternator issue or electric drain with key off

 

Great info, thanks!

I'm embarrassed to say that after fussing around with the trickle charger, measuring voltages and determining that it was a bad battery (reading 13V but still not able to turn the engine over), it turns out it was just a loose cable clamp.

I used to know enough to check that first thing.

I'll still check for parasitic draw through the battery neg cable after 30 min, and then those fuses if there is.