Autometer fuel gauge

[bronconut73]

Installed the new sending unit and voila my new Auto meter gauge is working.

I noted the position of the float at the bottom of it's stroke. Just a tad below the pick up screen. Seemed perfect.

My issue is, (it is an old Tom's 13 gallon poly tank) with less than 10 gallons in it the gauge reads way past full. I know the bottom of the float stroke is at a pretty good spot since 2 gallons didn't move it off of Empty. But when I dumped in approx 7 more gallons for a total of about 9 the gauge swung way past full.

Here's a dumb question.....

Is it going to be bad for my Autometer gauge to read way past full so much?

What has been your experience with the aftermarket fuel gauge installation?

I do have the correct ohm range gauge. You guys helped me with that too.

 

[bronconut73]

Has someone else used an Autometer fuel gauge in their eb with a stock sender?

 

[bronconut73]

Bump......

 

[DirtDonk]

Gettin' no love today from the bros, eh? Well, it's a weekend and hopefully some of them are out and away from the computers for awhile! I was actually working on a Bronco this afternoon! For once...
Can't help for sure either, since I've never used an aftermarket gauge with a stock sender, but they're designed to work that way, so should.

Lots of things can make variations though, from the input voltage, to the condition of the wires to the sender, to the ground, etc. Even whether the gauge itself or the sender aren't working quite right.
I doubt that it's going to hurt the gauge. It'd have to be truly pegged with no resistance to cause any harm I would think. Or would have to be completely un-dampened to where the needle just jumps up and smacks the limiting post each time you turn the key on.

I've never seen a factory gauge in an older vehicle that read from zero to full exactly. In my case, I set it so that it was at least evenly over and under the limits. So when on full, it's just above, and when out of gas it's just below empty on the gauge.
And that's with the standard range of a stock sending unit.

Personally I would want my old gauge to go well below empty when I'm running down. Too much tendency for us to wait to the last minute so a little leeway seems like a good idea.

Have you driven it yet? Emptied the tank, or driven it at least long enough to see what it takes to go below full? That's what I'd do first. Then see if there's anything you need to do to balance it out.
If it was a gauge made for a GM or Chrysler sending unit, I don't think it would read even remotely correct. The GM ones might even read in reverse!

Good luck. Maybe someone will know for sure, so back to the top for you.

Paul

 

[SSDDBRONCO]

Is it always reading past full? And just to make sure what are the ohms for the gauge? I have the autometer gauges and it doesnt read exactly correct but it's close enough

 

[bronconut73]

Thanks guys.
It is the 73 to 10 ohm range model. The gauge did not move with 2 gallons in it. So I figured that was good. I should have a small reserve in the tank when it is reading empty. When I dumped my overfilled 6.6 gallon gas can into the tank the gauge went from no reading to way past full. I am not complaining since I haven't had a functioning fuel gauge for years.
If it is not inaccurate on the empty end of the gauge, that will suck. It is OK if it has an odd full end of the gauge. Like Paul said I just need to drive it a bit and see if it straightens out. If not then I just need to get used to it's idiosyncrasies like the rest of the old girl.

 

[DuctTape]

I've got aftermarket fuel gauges and I regard them as more of a thumb in the wind than actual level. I'd guess you could try to dial it in with a variable resistor but I doubt it'd be worth it.

In my case the needle bounces as the float does. I go by what the slosh range is on the gauge more than anything else.

 

[bronconut73]

My gauge seems to be fine now. But like what was said above it is only a little better than holding your thumb to the wind. I haven't had a properly functioning fuel gauge in 20 years so to me it is awesome.

 

[roostracing]

bronconut73...

i have an autometer gauge too. What wires did you use to hook the gauge up to? I have 5 gauges and all im lacking is the fuel gauge. I dont know where to splice into.

 

[pbwcr]

Been there. If you want the meter to be accurate as possible then take the sender/float out to the bench and measure the resistance at the top & bottom and bend the rod accordingly. This means you need a jig of your own design that defines bottom and top of the tank and holds the sender assembly in the correct place relative to your jig. Of course you need an Ohm meter that will read 73 and 10 ohms. Not many guys have that meter.
Any way examine the rheostat and make sure it has goo contact and is not worn out.
When done you will a good reading, F & E . In between F & E you are at the mercy of Ford who designed the thing. It definitely is not accurate in the in between range.
PaulW

 

[bronconut73]

I traced the wire back from the main tank sending unit.
I believe it is orange. The other wire off the sending unit at the tank is just a ground.
I tied into the orange wire under the dash at the old fuel tank selector switch on the dash.
I am only using the main tank so this set up worked fine for me. I guess you could tie your fuel gauge into the wire off the selector switch where it heads to the stock gauge if you still run both tanks.

I have noted that the Autometer gauge reads way past full when I fill up and that had me thinking it would run out of fuel at a quarter tank but that is not the case as I have accidentally ran it down to the Empty line, even below it.

 

[trekgurl]

I have a Autometer fuel gauge and using the stock sending unit w/ 13 gal steel tank. The gauge reads way past full when I fill up (which is generally around 10 gals). It will stay pegged for a while and as I drive around I can tap on the gauge and it will start to read correctly. So it works a little erratic (but way better than a non working gauge like I'm used too for may years).

For me I can probably rule out any grounding issues as I have a new wiring harness and new grounds on the bronco and all the other specified places. I installed a new fuel tank and sending unit a few years before my re-wire due to previous rodent attack on my fuel system. When I put the sending unit in I didn't check anything with the sending unit so I may have something not quite right there?

I had thought about trying to use a Autometer Universal sending unit http://www.summitracing.com/parts/atm-3262/overview/ but it looks like one would have to try and modify the tank to make it work so that may be more trouble than it's worth.

 

[pbwcr]

bronconut73 and trekgurl,
Go back and read post #10 and keep the Ford sender. It is not calibrated for every version of the various tanks. You need to bend the float rod just like I did. There is nothing wrong with your wiring or the gauge you have.
PaulW