Fuel Gauge Info

[g4zur]

Hi All. TR7 2.0L 1980.
I will shortly be fitting a new fuel tank, As my fuel gauge has shown full since I got the car In june of this year I bought a new gauge sender unit and second hand Gauge from Robsport. First class service from them as always.
I checked the voltage produced from my charging system which came out at 13.9 volts from a recently fitted alternator. So decided to check out gauge and sender unit wired on the bench. readings as follows.
DC Power supply set at 13.9 Volts
Gauge reading full ...... 0.53 to 0.63 Volts
Gauge reading 3/4 ...... 2.71 to 2.75 Volts
Gauge reading 1/2 ...... 3.95 to 4.02 Volts
Gauge reading 1/4 ...... 4.88 to 4.97 Volts
Gauge reading Empty ..... 5.49 to 5.05 Volts
Variation read and recorded after many checks. hence the slight variations.
Full tank read 10 Ohms
Empty tank read 312 Ohms
Of course different gauges will vary slightly as will the variable resistor in the sender unit so figures for reference only.
All test carried out using calibrated test equipment so my figures can be trusted.
Just hope this will help someone in the future.
Also confirmed that empty shows empty and full shows full. However when connected to vehicle using the original OLD loom wires. I guess It will give slight resistance, I will see when fitted and update this topic.
Regards to all.
Gareth.


G.P.Albrighton

[jclay (RIP 2018)]

You have a short in the wiring to frame some where between the tank and the gauge.

Clay

[url="http://www.jclay.me/"]My Triumph Site[/url], [url="http://www.triumphtechnical.me"]Technical Stuff[/url], [url="https://docs.google.com/folder/d/0B8MWEvqOpX3udEF4SmFQUW9RS09hbU5uNW5Wd0xrUQ/edit"]My Public Folder[/url],

[g4zur]

Hi All.
As promised update on Fuel Gauge situation.
As mentioned in another Post, New tank and sender unit fitted.
The fuel gauge still showed full, Wireing or gauge was the problem.
I this morning took out the instrument pod and replaced the gauge with a second hand one I bought from Robsport, Gauge now works fine, I now have the sender unit and gauge I used on tests mentioned earlier in this post.
Very pleased to now have a fuel gauge, You were right Russ It was the same problem you had, Thanks for that[:)]
While Pod out I also removed the Green dash light shades and replaced the dash ilumination bulbs with red LED's Pleased with how it looks. Another job done.
Regards and Thanks
Gareth.


G.P.Albrighton