12 replies to this topic

[MR77LX]

Hey Guys

My fuel gauge has been playing up.
I have an aftermarket fuel gauge (auto Meter) and a new sender in my drop tank (LX Torana)
At first it was not reading at all until I ran an earth from my battery to the sender.
Now it only reads a quarter. I filled up 45l litres of fuel today and it
still read a quarter.
Anyway I started playing around with the wiring for the gauge and what i noticed is If I get my test light and and run it to the negative terminal of my gauge it actually reads a bit more than half way which I think is kinda accurate. However if I run a seperate earth to the gauge it goes back to reading a quarter and when I use my test
Light it reads a bit over half.

Any ideas on what the hell is going on would be great!

[S pack]

More info on exactly which Autometer fuel gauge you have and which make & model of fuel tank sender unit you are using would probably help.

 

Cheers

Dave.

[MR77LX]

The auto meter that I have is a AU 1316.
It's specs are 73 ohms empty and 8 to 12 ohms full.
The sender unit is just a rare spares one and the drop tank is a John Little drop tank.

[S pack]

Found this on the autometer site last night. Perhaps it might shed some light on your problem.

http://www.autometer.../faq_view/id/12

[neglectedtorana]

Guessing the test light is adding some resistance to the ground circuit,

Not sure why it would work but you could add a resistor and see what happens or try get to g an adjustable resistor pot from jaycar and see if you can find a happy range

[MR77LX]

Yea it got me stumbled.
I use a test light and the gauge reads half.
I use an earth wire and it stays on its original position (quarter) and does not move.

[S pack]

Did you read the AUTOMETER article in the link I posted? You may need to get the gauge recalibrated to suit the Torana sender unit.

Edited by S pack, 15 August 2016 - 01:23 PM.

[MR77LX]

Yes i did read it. You may be right regarding getting the gauge calibrated. 

[S pack]

Yes i did read it. You may be right regarding getting the gauge calibrated. 

OK, I just looked up the AU1316 Arctic white fuel gauge. It is listed as the Ford fuel gauge so it is calibrated to read empty at 50 ohms, half at 25 ohms and full at 10 ohms. According to the Autometer literature at 73 ohms the needle drops the needle thickness below empty.

 

Prob best to talk to an instrument repairer about your issue with a view to re-calibrating the gauge. My calculations for the Torana fuel tank sender unit are: Empty at 73 ohms, 1/4 tank at approx 55 ohms, 1/2 tank at approx 40 ohms, 3/4 tank at approx 25 ohms and Full at 10 ohms.

[MR77LX]

Before i speak to an instrument repairer, you dont think its got anything to do with how i wired my gauge?

Only reason is because i have 3 other gauges connected as well and they all use same power line. 

[S pack]

Before i speak to an instrument repairer, you dont think its got anything to do with how i wired my gauge?

Only reason is because i have 3 other gauges connected as well and they all use same power line. 

And those gauges all work fine?

Having another 3 gauges connected to the same 12v feed shouldn't be an issue unless the wire is too small for the job.

[MR77LX]

yea they all work fine