Learning about Fuel Gauge Senders . . .

[tpenfield]

As I mentioned in my stringer repair thread, my original sender did not fit in the opening in the tank. So, I went with the sender that came with the tank. The fuel gauge that came with the new tank seems to be mis-matched with the fuel gauge. The gauge goes up to 'empty' when the ignition is turned on. The most the gauge seems to go up is to about 1/2 reading when all the gas is at the back of the tank in the area of the sender.

So, I did some Googling of senders today and measured the resistance of my old 'VDO' brand sender.

My original sender looks like it is a 0-90 ohm resistance range, according to the ohmmeter.

It looks like there are '10-180 ohm' range and '33-240 ohm' range senders in addition to the '0-90 ohm' range senders.

Are there any others?

I have not measured the sender that is in the tank, but my guess is that it is a 33-240 ohm sender, based on the fact that the gauge went up to about 1/2 when all the gas was at the back of the tank during acceleration and getting on plane. I'll have to check the part number on the sender to make sure.

So, it looks like I should get a sender that will fit in the tank and have the 0-90 ohm range.

I am just wondering why there are 3 ranges and if there is anything particular about the 0-90 ohm range?

 

[JoLin]

Re: Learning about Fuel Gauge Senders . . .

Hi, Ted- pretty sure it's just a 'different strokes' proprietary difference among manufacturers, as you see the same thing in the automotive world. As for VDO's 0-90 range, the only thing 'special' about it is that you need to match it.

 

[Silvertip]

Re: Learning about Fuel Gauge Senders . . .

To determine what gauge and sender you have you only need to disconnect the pink sender wire at the sender and then measure the resistance from the sender to ground. 33 ohms full, 109 (roughly) half full and 240 ohms empty. Next, connect a 90 ohm resistor to the pink lead and touch the other end to ground If it is a 0-90 ohm gauge it should show empty. Next, touch the tank end of the pink wire to ground. The gauge should peg full. If the gauge shows about 1/2 full with a 90 ohm resistor, you have a 33-240 ohm gauge. If it shows empty with a 90 ohm resistor you have a 0 - 90 ohm gauge and need a 0 -90 ohm sender.