Nothing wrong with a gauge, but to me it seems like a lot of engineering and modification for little gain. I've never had a working light and rarely carry a stick because the odometer in a T-Series is quite accurate. If I've gone 200 miles then I know I need to start thinking about fuel soon. Or you can look down into the tank before setting off and gauge fairly accurately how many gallons are in there. Not many people can outlast a tank of fuel in an old sports car anyway, either due to bladder or cramps.

I found you this link
http://dennis-carpenter.com/fuel-tank-sending-unit/p/99A-9275/


It's a shame, you should dismount your gauge and fix it!
Here is what we find
 
First of all a stick in bakelite which allows to isolate the contacts.
It is achieved with the tilting of two brass blades actuated by the float that come into contact with the right blade itself connected by an insulator on the thread of the light of the gauge (at the top). Between the movement of the blades operated by the float, there is a wire at the origin of a single strand to ensure the flexibility of the movement. It was wrapped around the axis of the brass nut, the continuity being through the flexibility of the wire during the tilting of the float.

At the beginning this wire was wrapped around the bakelite stick, I do not know.
On mine, this little thread was broken.
I chose to put a wire of several strands to allow greater flexibility that I soldered to the nut at the bottom.
Wire that I fixed on the body of the case and that I connected to the mass.
Since then, my gauge gives me complete satisfaction. Here is my experience that I wanted to share with you.
Sincerely, Thierry de l'Ardèche, South of France

How far do you drive? My preflight is to check fuel level, each gallon is worth 20 miles, I never let it get below half tank anyway.

Peter

I agree, my bladder needs to be emptied more often than the tank needs to be filled.

I started taking long rides in late 2017 and found I needed to see my fuel level as much as I needed to see my water temp and oil pressure. Not being able to see my fuel level was an annoyance. If I can unobtrusively mount a fuel gauge where I can see it and not disrupt the look of the TF interior I'd like to do it. I'm still noodling on where to put the gauge so I can see it and not lose points at car shows. Right now thinking glove box on passanger side. I have a glove box door I can use at shows.

BTW, I had my prostate fixed by Cooled Thermo Therapy years ago so I'm back to having a bladder like I was 30.

Thierry,

Thanks for your post! I wondered how that worked. As a new MGTD owner on the journey to getting a car back on the road, tips like this are gold.

Regards,
Chuck

Chuck,
I have other photos if you want. Just ask.
Remember to plan to change the seals Moss 293-401
They are well glued during disassembly.

I found the link on MGAguru.com which confirms that the bakelite stick was beautiful and well wound with fine thread to constitute resistance.
http://mgaguru.com/mgtech/electric/et214.htm

Sincerely, Thierry de l'Ardèche, South of France



Edited 1 time(s). Last edit at 2019-02-10 02:00 AM by MGTF1500 Ardeche France.

Just did this project on a different make of antique car. I found this capacitive fuel probe which does the job very accurately and with no moving parts at all. I will post a link to the EBay ad at the end of this.
What the ad does not tell you is that the probe puts out a varying voltage (0 to 5V) depending on the fuel level. Using two small screws you adjust pots to set the probe for full and empty, and in this way you can cut it to length as needed in your tank.
Unfortunately it puts out a voltage and all of the modern day gauges want to see a resistance. Well for another twenty bucks this outfit will sell you a converter that will not only convert the signal to something that any fuel gauge you can purchase will accept but it will compensate for your tank not being linear. ( like fatter at the bottom than at the top)

This setup is quite accurate, cheap and has no moving parts. I have one in my other car and it works great.

https://www.ebay.com/itm/Fuel-level-sender-capacitive-type-no-moving-cut-to-length-6-6-10-0-5-5V-output/261667388910?hash=item3cec977dee:g:YdsAAOSwwKtZi3FE:rk:2:pf:1&frcectupt=true

This device sounds great but how would it work for a T series tank? It appears this device is designed for tanks that lay horizontal and the T series is vertical. Not sure this is the right device for our cars. JMO.

That is just one of the issues, we want to avoid solutions that require cutting a new hole in the tank as well. That means it needs to fit via the filler cap or where the existing low level fuel float fits via the back of the tank. Obviously there may be new workable ideas, but I know that Declan Burns looked at every possible option he could find before developing his own solution.
Dave H

It is designed to measure depth.
Therefore it would have to be mounted on the top of the tank.
Special probes are made for aircraft fuel tanks that lie flat.
There is a model of the probe that is flexible for the first four or five inches. You could cut your hole in the back-top of the tank and then put a 90 degree bend in it.

I am not convinced that many would be prepared to cut a hole in the tank. My version should fit through the original aperture. That is the reason I use two sensors, one measures from the top of the tank to the aperture and then the second sensor, which is connected in series, measures from the aperture to the bottom of the tank. I also have a separate reed switch in the lower sensor to drive the low fuel lamp on the dash board.

Regards
Declan

Declan, I can see how the main sensor will enter the tank, but how do you get the low fuel sensor in and connected? PJ

Declan,
Your concept model looks impressive and makes all the sense in terms of how it should work when mounted in the tank. Just one question. Is it difficult to insert your design into the existing sending unit tank hole when there are two tubes going in opposite directions on your unit?

Declan,
Never mind I just figured it out. The lower tube is inserted first and the wires left hanging out of the tank hole. Then thread those wires through the hole in the mounting plate and then insert the longer or top tube into the tank. Thread the outer nut onto the lower tube after pulling it tight using the wires. Simple and brilliant. Just want to make sure I understand. Last question: how do I make sure I have the lower tube positioned perfectly vertical and not cocked to one side or the other after tightening the outer nut?