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Fuel gauge resistance?!

Posted: Wed Sep 27, 2017 9:40 am
by broompisces
Hello all,
I am replacing my 49 year old internal fibreglass fuel tank in my Broom Pisces - mainly because it leaks like a sieve!
A local precision engineering company will be making me a new tank from stainless steel, using the current tank as a template.
I am going to order a new fuel sender for the new tank (the magnetic float "pole" type), whilst still using the original fuel gauge.
I was poised to order a fuel sender when I noticed that they come in different resistances; 0-190 ohm for European fuel gauges and 230-30 ohm for USA fuel gauges.
Now, my fuel gauge is an original 1960's Mercruiser one - should I be going for the 230-30 ohm sender unit or the 0-190 ohm one?
Many thanks in anticipation of your help / advise.
Ian.

Re: Fuel gauge resistance?!

Posted: Thu Sep 28, 2017 5:39 pm
by Diomedea
Not trying to appear obvious but can you measure the resistance of the old one?

Re: Fuel gauge resistance?!

Posted: Sat Oct 14, 2017 11:09 am
by broompisces
I measured the resistance.

However - the meter read circa 90 ohms when it was attached to two posts on the fuel gauge. But my choice for fuel sender is a 230 - 30 ohm sender or a 0 - 190 ohm sender.

Can anyone advise what a resistance of circa 90 ohms across the fuel gauge would indicate which sender I should get? I disconnected all wires from the gauge before testing the resistance.

Diomedea; the reason I hadn't measured it was the distance from my home to where the boat is wintered. I was hoping someone on the forum would've known.

Anyway - after a morning jaunt to the boat yard, I at least now know what resistance the meter across the gauge yielded!

Re: Fuel gauge resistance?!

Posted: Sat Oct 14, 2017 8:58 pm
by haventaclue
If your gauge is USA made,then you need a 0-190 sender.Also Sent PM.

Re: Fuel gauge resistance?!

Posted: Fri Oct 20, 2017 3:42 pm
by broompisces


Got my new fuel sender; seems to work well!

Re: Fuel gauge resistance?!

Posted: Fri Oct 20, 2017 3:50 pm
by broompisces
I decided to go for the 240 - 30 ohm sender as the fuel gauge is an original 1960s one. Looks like I guessed right as the video above shows. Usually, if I have a choice of two items; one right and one wrong, I always choose the wrong one. The picture below shoes the old sender and the replacement one.

Re: Fuel gauge resistance?!

Posted: Fri Oct 20, 2017 4:00 pm
by broompisces
Here's the fuel tank - nearly 50 years old and leaks like a sieve. Once replaced, It'll be nice not having the sniff of 4 star mixing with the natural air of Loch Lomond.