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Fuel sender and fuel gauge don't match
Northy - 21/5/24 at 12:08 PM

Hi all,

My fuel sender has never matched my fuel gauge, it works backwards and not over the full range
I'd rather not change either of them if I can, is there anything clever that I can put between them to make them work together?

Thanks,

G

MikeR - 21/5/24 at 12:42 PM

gauge magic sometimes sold on ebay. If you google Andrew Reville you used to be able to find all the details to make it yourself.

rusty nuts - 21/5/24 at 01:51 PM

Fuel gauge wizard

Northy - 21/5/24 at 01:52 PM

Great stuff, thanks. I think I've found al the details.
Has anyone in here built one? The guy seems to have gone quiet for a while.

G

MikeR - 21/5/24 at 02:12 PM

He's active on the caterham forums. This isn't his key focus on life.

Northy - 21/5/24 at 02:44 PM

quote:
Originally posted by MikeR
He's active on the caterham forums. This isn't his key focus on life.


Ah, thanks. Does he still answer questions at all?

G

nick205 - 21/5/24 at 03:16 PM

I know your pain Northy.

When I built my MK Indy I used the Ford Sierra fuel level sender with an ETB fuel gauge. It worked, but

Full tank = Full gauge

Empty tank = Half gauge

Fine if you knew how it worked, but always a niggle I wanted to correct.

Northy - 22/5/24 at 03:45 PM

quote:
Originally posted by nick205
I know your pain Northy.

When I built my MK Indy I used the Ford Sierra fuel level sender with an ETB fuel gauge. It worked, but

Full tank = Full gauge

Empty tank = Half gauge

Fine if you knew how it worked, but always a niggle I wanted to correct.


I might look at building one if you're interested. I need to read into it more when I get more time.

G

nick205 - 23/5/24 at 11:08 AM

quote:
Originally posted by Northy
quote:
Originally posted by nick205
I know your pain Northy.

When I built my MK Indy I used the Ford Sierra fuel level sender with an ETB fuel gauge. It worked, but

Full tank = Full gauge

Empty tank = Half gauge

Fine if you knew how it worked, but always a niggle I wanted to correct.


I might look at building one if you're interested. I need to read into it more when I get more time.

G



Appreciate the offer, but I sold the Indy a long time ago (multiple kids and the need for different transport). I was OK seeing it go, but eldest son (6 at the time wasn't).

Schrodinger - 23/5/24 at 06:35 PM

Can the sender float be adjusted?
I have an ETB sender which has the float on the end of a long wire lever, iirc you can remount the float so that it works 180 deg from normal if that makes sense.

Northy - 24/5/24 at 11:03 AM

quote:
Originally posted by Schrodinger
Can the sender float be adjusted?
I have an ETB sender which has the float on the end of a long wire lever, iirc you can remount the float so that it works 180 deg from normal if that makes sense.


Mines a tube type sender, can't remember the proper name. I had to use that as the tank is baffled.

G

Mr Whippy - 24/5/24 at 11:30 AM

quote:
Originally posted by Northy
Hi all,

My fuel works backwards



Replicar328 - 29/5/24 at 05:48 PM

I've had a look at the "gauge magic" download and it looks like an Arduino based device which I'd argue is a bit overkill for a fuel gauge which is a fairly simple device.

Essentially, the "sender" is a variable resistance which simply alters the current flowing through the meter. If you are able to measure the resistance of the sender when the tank is full and when it is empty and to use a potentiometer in place of the sender to test what resistances show full and empty on the gauge then I can sketch you a schematic of an analogue circuit which should do the trick.

But I don't know how to post pictures on this forum?

Schrodinger - 29/5/24 at 08:57 PM

What makes are your sender and gauge?

[Edited on 29-5-24 by Schrodinger]

scudderfish - 30/5/24 at 10:23 AM

quote:
Originally posted by Replicar328
I've had a look at the "gauge magic" download and it looks like an Arduino based device which I'd argue is a bit overkill for a fuel gauge which is a fairly simple device.

Essentially, the "sender" is a variable resistance which simply alters the current flowing through the meter. If you are able to measure the resistance of the sender when the tank is full and when it is empty and to use a potentiometer in place of the sender to test what resistances show full and empty on the gauge then I can sketch you a schematic of an analogue circuit which should do the trick.

But I don't know how to post pictures on this forum?


I was planning on doing something similar with an ESP32 so I could wifi enable my fuel gauge

Replicar328 - 30/5/24 at 10:24 AM

quote:
Originally posted by Schrodinger
What makes are your sender and gauge?

[Edited on 29-5-24 by Schrodinger]


Good question. I've googled typical sender resistance ranges and there are a host of different values. Typically the EU uses the VDO standard of 0 to 180 ohms and the USA 30 to 240 ohms but that is in no way universal and low to high resistance can be empty to full and vice versa. Out of interest I think I'll build an analog circuit to invert the direction and change the scale but I also stumbled across https://www.ebay.co.uk/itm/404392578717 which seems like a quick and easy solution.

Northy - 4/6/24 at 09:09 AM

My gauges are CAI units, bt don't seem to be available these days? Are they no more?

G

Schrodinger - 4/6/24 at 09:12 AM

Do you know what the resistance is at full/empty? ETB do make tube sensors and may be able to make one for you.

SteveWalker - 4/6/24 at 01:38 PM

quote:
Originally posted by Northy
My gauges are CAI units, bt don't seem to be available these days? Are they no more?


CAI is Caerbont Automotive Instruments. They are still around and are the manufacturers of Smiths gauges.

Northy - 13/6/24 at 10:13 AM

Do they still make individual gauges? I can't see any for sale like mine.

G

[Edited on 13/6/24 by Northy]

MikeR - 13/6/24 at 12:01 PM

They still respond to requests for technical advice - i've had responses the next morning to my questions.

Northy - 13/6/24 at 03:08 PM

Thanks, I'll eventually get in touch with them about mine.

G