Fuel Gauge Terminals
Discussion
Hi can anyone help me identify the following terminals on my Carbonate fuel gauge?
Caerbont cunningly just labelled the terminals 1, 2 & 3
I can work it all out with a meter but I was just wondering if anyone was familiar with the Caerbont mystery 123 labelling system.
Thanks, Dave.
- one terminal is earth
- one terminal is +12V
- one terminal goes to the sender
Caerbont cunningly just labelled the terminals 1, 2 & 3
I can work it all out with a meter but I was just wondering if anyone was familiar with the Caerbont mystery 123 labelling system.
Thanks, Dave.
Sussed it 
Just in case anyone is interested here's the terminal layout.
And here's how to wire a Fuel Gauge Wizard so you can read a reversed Ohm LPG sender signal on a TVR Caerbont petrol gauge.
No more looking in the boot at the tank gauge or setting the trip meter to make sure I dont run out of gas.
Happy days
Have a look at the Fuel gauge Wizard gauge calibration solution and other clever ideas here:
https://www.spiyda.com/magento/index.php/
Just in case anyone is interested here's the terminal layout.
And here's how to wire a Fuel Gauge Wizard so you can read a reversed Ohm LPG sender signal on a TVR Caerbont petrol gauge.
No more looking in the boot at the tank gauge or setting the trip meter to make sure I dont run out of gas.
Happy days
Have a look at the Fuel gauge Wizard gauge calibration solution and other clever ideas here:
https://www.spiyda.com/magento/index.php/
ClausB said:
Hi Dave,
thanks for bringing this up - I am wondering if this couldn't be used for matching the RR coolant temp sender to the Late caerbont gauges.
Claus
Yes it can Claus, and it'll give more accurate & consistent results than the simple 170 Ohm resistor people use when doing the Range Rover sender mod.thanks for bringing this up - I am wondering if this couldn't be used for matching the RR coolant temp sender to the Late caerbont gauges.
Claus
But you will need to calibrate the Wizard against a known true temperature reading.
You just need the RoverGauge software if you're still on the 14CUX, if you're on a stand alone ECU obviously you'll see the true temperature on that software.
The Gauge Wizard is a handy & clever little box of tricks, and it's not too expensive either.
Hey Dave - sort of slightly related question - do you know whether the mounting for the fuel guage sender in the Chim tank is a standard fitment? i.e. Can I bolt in pretty much any sender or does it have to be a specific Chim one?
I've got my new dash on order, gauges lined up, one of those fuel sender wizards (somewhere - I must start remembering where I put sh*t that I buy) but my sender doesn't actually work until 1/4 of a tank has gone. Just trying to decide whether I need to buy a new sender from a TVR dealer or whether I need to buy a new sender from where I get the gauges from.
Phil
I've got my new dash on order, gauges lined up, one of those fuel sender wizards (somewhere - I must start remembering where I put sh*t that I buy) but my sender doesn't actually work until 1/4 of a tank has gone. Just trying to decide whether I need to buy a new sender from a TVR dealer or whether I need to buy a new sender from where I get the gauges from.
Phil
Hi Phil,
If I understanding correctly you have a new fuel gauge & you want the TVR sender to work with it?
Firstly you need to establish if the issue you describe is mechanical or electrical.
Start by eliminating the mechanical side by removing the sender from the tank & manipulating it throughout it's full range while watching the gauge.
You may just find the float was fouling on the inside of the tank, which is quite common.
Then you need to establish the resistance of your TVR sender & the resistance your new gauge works at.
I bought a 200mm sender for my auxiliary petrol tank, on the face of it this should have been perfect but it ended up in the bin.
We soon discovered the TVR gauge worked in the opposite direction to the sender, it turns out I could have sorted it with a Fuel Gauge Wizard but I didn't know about it then.
Keith ended up adapting my old TVR sender to the boss he'd welded to the tank, so the sender fittings must have been different.
By shortening the float arm so it was better suited to my 200mm deep auxiliary petrol tank he got it working extremely well.
Which was a nice surprise as you might assume the range could still be a bit out, but I can confirm full is full, empty is empty and everything in between is accurate too.
However, it's a bit trickier with the LPG sender.
The TVR petrol gauge works on a 250 - 0 Ohm range (0 Ohms full & 250 Ohms empty).
The LPG sender works on a 0 - 90 Ohm range (90 Ohms full & 0 Ohms empty).
Or is it the other way round, cant quite remember, but they are definitely working in an opposite way to each other.
Anyway the only way I'm going to get the LPG sender working with my TVR gauge is to use the Wizard which solves the reversed resistance issue and allows compensation for the different working range.
The Wizard not only solves the reversed resistance issue but provides adjustment for:
So not only full is full & empty is empty, but everything in between is spot on too.
The Wizard is a clever box of tricks, but you do need to spend some time tweaking all three areas of adjustment to get everything working spot on.
I took the easy option & sent a spare LPG sender & my TVR gauge up to Chris at Spiyda Design and he calibrated everything for me on his bench.
I'm fitting it tomorrow, lets see how it goes
If I understanding correctly you have a new fuel gauge & you want the TVR sender to work with it?
Firstly you need to establish if the issue you describe is mechanical or electrical.
Start by eliminating the mechanical side by removing the sender from the tank & manipulating it throughout it's full range while watching the gauge.
You may just find the float was fouling on the inside of the tank, which is quite common.
Then you need to establish the resistance of your TVR sender & the resistance your new gauge works at.
I bought a 200mm sender for my auxiliary petrol tank, on the face of it this should have been perfect but it ended up in the bin.
We soon discovered the TVR gauge worked in the opposite direction to the sender, it turns out I could have sorted it with a Fuel Gauge Wizard but I didn't know about it then.
Keith ended up adapting my old TVR sender to the boss he'd welded to the tank, so the sender fittings must have been different.
By shortening the float arm so it was better suited to my 200mm deep auxiliary petrol tank he got it working extremely well.
Which was a nice surprise as you might assume the range could still be a bit out, but I can confirm full is full, empty is empty and everything in between is accurate too.
However, it's a bit trickier with the LPG sender.
The TVR petrol gauge works on a 250 - 0 Ohm range (0 Ohms full & 250 Ohms empty).
The LPG sender works on a 0 - 90 Ohm range (90 Ohms full & 0 Ohms empty).
Or is it the other way round, cant quite remember, but they are definitely working in an opposite way to each other.
Anyway the only way I'm going to get the LPG sender working with my TVR gauge is to use the Wizard which solves the reversed resistance issue and allows compensation for the different working range.
The Wizard not only solves the reversed resistance issue but provides adjustment for:
- Gain
- Linearity
- Offset
So not only full is full & empty is empty, but everything in between is spot on too.
The Wizard is a clever box of tricks, but you do need to spend some time tweaking all three areas of adjustment to get everything working spot on.
I took the easy option & sent a spare LPG sender & my TVR gauge up to Chris at Spiyda Design and he calibrated everything for me on his bench.
I'm fitting it tomorrow, lets see how it goes
Edited by ChimpOnGas on Friday 10th May 08:23
ChimpOnGas said:
Yes it can Claus, and it'll give more accurate & consistent results than the simple 170 Ohm resistor people use when doing the Range Rover sender mod.
But you will need to calibrate the Wizard against a known true temperature reading.
You just need the RoverGauge software if you're still on the 14CUX, if you're on a stand alone ECU obviously you'll see the true temperature on that software.
The Gauge Wizard is a handy & clever little box of tricks, and it's not too expensive either.
Exactly that was the idea - as with adding the 170 Ohm resistor I can match the sender and the gauge at one temp only. I've ordered the gauge wizard yesterday and will post some pictures after installation.But you will need to calibrate the Wizard against a known true temperature reading.
You just need the RoverGauge software if you're still on the 14CUX, if you're on a stand alone ECU obviously you'll see the true temperature on that software.
The Gauge Wizard is a handy & clever little box of tricks, and it's not too expensive either.
Claus
Ok it's official....
Fuel Gauge Wizard rocks
Fitted it this morning and....
Start with empty tanks...
Nip down my local LPG station & stick 25 litres of gas in (half fill).
Turn ignition on & hey presto, half full of LPG displayed on my second TVR petrol gauge.
Seems simple right?
It isn't
Little things please little minds I guess, but what a cool thing the Fuel Gauge Wizard is
Fuel Gauge Wizard rocks
Fitted it this morning and....
Start with empty tanks...
Nip down my local LPG station & stick 25 litres of gas in (half fill).
Turn ignition on & hey presto, half full of LPG displayed on my second TVR petrol gauge.
Seems simple right?
It isn't
Little things please little minds I guess, but what a cool thing the Fuel Gauge Wizard is
Excellent Dave.
That is the kind of detail that finishes the job, rather than having a half-baked solution, or none at all.
Either of which would have remained a constant niggling annoyance for years to come.
The few people that I have mentioned your project to, have said much the same thing; he will never really know how much LPG he has...
You may have a much wider audience for a true working solution than the Chimaera forum I think.
That is the kind of detail that finishes the job, rather than having a half-baked solution, or none at all.
Either of which would have remained a constant niggling annoyance for years to come.
The few people that I have mentioned your project to, have said much the same thing; he will never really know how much LPG he has...
You may have a much wider audience for a true working solution than the Chimaera forum I think.
Goaty Bill said:
Excellent Dave.
That is the kind of detail that finishes the job, rather than having a half-baked solution, or none at all.
Either of which would have remained a constant niggling annoyance for years to come.
The few people that I have mentioned your project to, have said much the same thing; he will never really know how much LPG he has...
You may have a much wider audience for a true working solution than the Chimaera forum I think.
Cheers mate, I am firm believer there's a solution for everything.That is the kind of detail that finishes the job, rather than having a half-baked solution, or none at all.
Either of which would have remained a constant niggling annoyance for years to come.
The few people that I have mentioned your project to, have said much the same thing; he will never really know how much LPG he has...
You may have a much wider audience for a true working solution than the Chimaera forum I think.
We are fitting the newly designed daughter board to the Wizard tomorrow.
This has 22 fine adjustments to compensate for slosh, it also has a low fuel warning out for an LED.
We may even use the signal to operate the changeover switch, so when I get low on gas the system automatically switches to petrol.
Next up will be a second pickup in the petrol tank to eliminate the very slight fuel starvation on hard left hand bends when the petrol is very low.
Then comes the 62cc Orange dot injectors, down slightly from the 72cc Yellow dots we are expecting further economy gains with some mapping and a drop in vaporiser pressure.
Finally a bit more fine adjustment of the multivalve to squeeze in another 4.5 litres and I'm ready to have the tanks trimmed in boot carpet.
I've done 2,500 trouble free miles on gas so far & it's been fantastic, I just need to achieve the 285 mile gas range by squeezing the extra gallon of LPG in and improving the economy slightly on light load cruise.
I'ts so close to greatness already, I'm absolutely determined to push the project the last mile to get it perfect.
Then its just a case of driving it down to the South of France for a proper test
gerradiuk said:
So Dave, my little Sketch of using 1 gauge for both fuels of no help to you ?
I've looked at the one gauge option a number of times and may still do it.But for now I kind of like seeing the level of both fuels at a glance on gauges that are next to each other, & without the need to hit a switch.
It defiantly needs the daughter board we'll be fitting tomorrow, LPG seems to slosh like crazy but the board should sort that.
Thanks for the instructions though, like I say I may still go with the one gauge option.
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