Low Level Fuel Light Flashing

[Woolly]

Hi All,

I read the article in this months magazine by Henri Van Triest on how to overcome the annoying low fuel warning light flashing at a quarter full. Guessed the reason was missing baffles in the tank but didn’t know there was and a fix for it. Looked well within my skill set so off to Amazon to order the 12V DC Delay relay. Unfortunately all 3 codes given came back unfound. Can anyone point me in the direction of what I actually need.

Many thanks

[andrewc]

Look on Ebay for 12V NE555 Timer and you will find several hundred hits. I used a 10 second one set to 10 seconds and put it behind the speedo. It is a lot easier to put it in the boot though. I would advise a 1 Amp fuse in the 12V supply.12v ne555 timer. This sort of thing is what I used but I can't remember the supplier.

https://www.ebay.co.uk/itm/DC-12V-Delay-Relay-Shield-NE555-Timer-Switch-Module-0-10-Second-Adj-UK-Seller/184186021596?hash=item2ae257a6dc:g:Z6MAAOSwpJReVRkg

Hope that helps.

[andrewc]

I just looked at that article again and see it has not been insulated but is sitting on Velcro on a metal tank!
I think the supply to the fuel pump goes from the battery via the ignition relays and the inertia switch to the fuel pump with no fuses in circuit.
If the wrong part (+12V) of your new circuit touches the metal of the fuel tank it will stop the car and may well burn out part of the wiring loom ...or worse!.
As I said before, in my opinion it should have its own small inline fuse and also it should be housed in something like this https://cpc.farnell.com/multicomp/g1...2mm/dp/EN85418
The link to that enclosure is just for illustration I haven't made certain it is the right size but there are hundreds available.
The right way is the safe way.

[andrewc]

I Meant to say I put mine in heavy duty heatshrink tubing as I was short of space so that is another option.

[StagJonno]

Yes, the fuel pump circuit is unfused, so definitely recommended that you fit an inline fuse for any extension, as well as protecting the timer.

[dasadrew]

had the same problem finding the one he used - found it on Amazon in Germany here:

https://www.amazon.de/gp/product/B01MS74NQP/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Drew

[Jeff]

https://www.socforum.com/forum/forum/stag-owners-club/soc-forum/13349-fix-flashing-fuel-gauges-for-a-fiver

[tvrgeek]

Very timely. Just ordered a new tank sensor as mine was a bit high resistance and the low switch was bad. So I never experienced the problem. Think I'll add a fix like this to mine.
I wonder, would not just a long time constant RC circuit be easier? More to play with!

[tvrgeek]

Of course, if you wanted to get fancy, an Arduino for about $8 could be programed to monitor all your sensors. Signal a single yellow light if something is getting close and red for " look at your gauges". I remember seeing a pro rally car where in front of the driver was one big light. No gauges. ( shift light) So many things to play with.

[Woolly]

Andrew - For some peculiar reason I didn’t think of eBay... Did a search including the full unit description word for word and limited to UK only and found the exact same unit. Straight in the shopping basket and with me in a few day. Once received and I can get the physical dimensions I will also order a suitable enclosure.

I will include an inline fuse.


Thanks to ALL

[markmark2]

Hi, Does anybody know how much fuel is actually left in the tank when the fuel light becomes permantly on?
Cheers
Mark

[jakesmig]

I had the same problem regarding the numbers but wrote in the item description, as from the article, and up came the appropriate part.
John.

[mallardstag]

Hi, Does anybody know how much fuel is actually left in the tank when the fuel light becomes permantly on?
Cheers
Mark

The answer is different for every car. Mainly due to bending of float arm and switch alignment. In mine it's about 1.5 imp.gal.

[tvrgeek]

Ordered a $2 timer board from Amazon. Also bought generic window switched ( 2 for $7, not $41 each) and a generic switch for the cabin lights ( $12, not $42) As I have make a new console plate anyway, slight size difference does not matter. USB outlet will replace the cigar lighter. New float in it's way from England. I hope to mock up the float on the bench so I can calibrate it for the bottom quarter of the tank where it is most important. Either by bending the tabs or wire, or by series/parallel resistors. Fun. I was able to make a new Smiths voltmeter read correctly by replacing the calibration resistor with the correct value. It was off by more than a volt!

[markmark2]

The answer is different for every car. Mainly due to bending of float arm and switch alignment. In mine it's about 1.5 imp.gal.

Thanks for the reply. Mark