Autometer Electric Fuel Pressure

[KySilverado]

Guys,
Wanting to pull fuel pressure into my scans. Went gathering info to make a custom PID but found that its already there.

Anyway... don't know what signal wire to use for the input. Looks like 3 wires coming from the sender.

Black
Grey
Purple

Searched this forum and been to Autometers but nothing on which wire is which. In the manual I downloaded from Autometer it does mention the signal output and ground from the back of the gauge for their brand data logger but hoping to just intercept it from the sender wiring so I don't have to dig into the gauge.

[KySilverado]

Just for those that may do this. You can't pull the EIO signal from the sender. Nothing coming from it over 1 volt.

You have to pull the signal from the gauge itself.

[John_F]

Which wire from the gauge?

[KySilverado]

Which wire from the gauge?

Mine didn't have a wire coming from it. I had to add it. Pin 10. You can buy a wire harness that will have it. Check at the end of this manual.

Autometer Manual

[John_D.]

I tried connecting my Autometer to my EIO yesterday, and it's not working right. Scanner shows 19.8 psi.

I have 3 wires between the sender and the controller.
Hot, ground, signal (white).

I have 3 wires between the controller and the gauge.
Red, green, brown. None of those 3 are labeled.
Those three are in addition to the 2 wires for the backlight.
There is no 10 pin connector anywhere in this setup.

I connected to the white signal wire coming from the sender.
That apparently isn't the right one.


The correct wire may be one of the three going to the gauge.
I'm guessing the red is a 12v feed.
If so, that narrows it down to the green or brown.
Anybody know which one for sure?

And if it follows the .5v-4.5v = 0psi-100psi ratio?
(volts/.04 - 12.5)

[John_D.]

I have 3 wires between the sender and the controller.
Hot, ground, signal (white).

I have 3 wires between the controller and the gauge.
Red, green, brown. None of those 3 are labeled.

The correct wire may be one of the three going to the gauge.
Anybody know which one for sure?
And if it follows the .5v-4.5v = 0psi-100psi ratio?
(volts/.04 - 12.5)

Got it figured out. I have an older version of the fuel pressure gauge. Instruction sheet dated 2001, vs. the more current one dated 2002.
The older version used a black plastic controller box between the sender and gauge.

The white wire from the sender was the correct one after all, I just had a bad connection to it.

The green wire to the gauge has a similar voltage range, but different. I didn't bother mapping it out, since the white wire has what I need. It appears to map correctly.

volts/.04 -12.5 is the correct setup.

[Perforator]

Here is a pdf I received from Auto Meter with a diagram of the pinout for future reference. They use the same pinout for all the Ultra Lite electric gauges.

[Perforator]

Oh and the formula is "The equation would be -.5 volt off of the reading, that that number divided by .04."

[John_D.]

In my hptuners I don't have an option to subtract .5 from the voltage.
However, I can subtract 12.5 psi from the result, which has the same effect.
(.5 volts / .04 = 12.5 psi)