'36 President fuel sender ohms value?

[Batwing-8]

All: I need to replace an incorrect (and inaccurate) fuel tank sender with a suitable replacement unit. Does anyone know the ohms range for the original '36 President Studebaker sender? (#187110) Thanks, Bill.

[Gary_Ash]

I think they are all 240-33 ohm units.

[SMB]

I don't believe that is correct. I believe the correct range is 0-30 ohms for that year. There are several ranges depending on the gauge being used. Try Tanks, Inc. for more information. I have a tank and sending unit for a 41 Chevy in my 37 President - 0-30 ohms and it works with the original gauge.

[Batwing-8]

Thanks guys........ To avoid purchasing multiple senders in an attempt to get the correct ohms value, I've ordered a simple variable rheostat of known range and will attempt to work backwards, adjusting the rheostat and noting the settings at which the gas gauge deflects through the complete full-to-empty range. Hopefully I can thus identify the original designated ohms values for the gauge.

[studerex]

Nice idea. let us know the results.

[Batwing-8]

Rex: Received the rheostat today:

1) Tested 0-200 ohm rheostat with ohmmeter to verify range and "linearity" of the readings. All appears OK.

2) Placed rheostat at (outside) fuel tank of car. Attached lead from gas gauge and also a ground. Adjusted rheostat with following results:

0 ohms = gas gauge reads "full"

36 ohms = gauge shows half-full

80 ohms = gauge at quarter-tank

200 ohms = gauge not quite pegged on "E"

The gauge requires no resistance in order to to read "full" and will require slightly over 200 ohms to read "empty." In addition, as seen by the progression of the numbers, the gauge doesn't read in a straight line........... 36 out of 200 ohms to reach half-tank and another 164+ to go the rest of the way to "empty."

So, this suggests to me either the gauge is out of calibration, OR the original Studebaker sender did not deliver its measurements in straightline readings. Thoughts????????????????

[Spinneyhill]

Maybe that us because the sender is mounted near the top of the tank and the float runs through an arc of about a quarter-circle as it falls, so to go from half to empty goes through much greater travel (arc) than full to half? Do some geometry and look at vertical chord lengths through the float as it falls. Then compare those chord lengths with the arcs travelled by the float. It will not be a linear relationship between chord length (fuel level) and the arc through which the float travels.

This difference can be minimized by setting the centre of rotation of the float some distance down into the tank. My Dodge uses a wee gear mounted about 100 mm down to get from a horizontal axis of rotation (for the float) to a vertical axis (to take the movement to the rheostat).

[studerex]

When I did the Peking to Paris President I added a fuel cell for longer distance. I used one of these sending units and was very impressed with how it worked. http://www.fuelsafe.com/catalog/Page-30.html

[Batwing-8]

Good advice all! Now, I'm thinking that my gas gauge must be out of calibration, because no manufacturer offers a 0-200 ohm unit. Sooooo, looks like I need a '36 President fuel gauge, part #188372. Anyone have one available? Thanks, Bill. (bill.allard@comcast.net)

[SMB]

Again, I think you are on the wrong track. Why to you think you need a 0-200 ohm unit? As I said 0-30 ohms works with my 37 President gauge and that was common in the 30's. Did you speak to the people at Tanks Inc.? Did you look at their website where they list the various sending units and their ohm values? If your gauge is moving it would seem to be that the sending unit is bad. Have you researched how to test the gauge by grounding it? It is pretty simple.

[Batwing-8]

SMB: Thanks for trying to keep me out of trouble! Here's what I know thus far:

1) If I remove and ground (no resistance) the "hot" lead at my car's fuel sender, the gas gauge goes to "full." This suggests one value on the sender needs to be "0". Next, is "what ohms-value is needed to bring the gauge to "'empty"?

2) To that end, I purchased an adjustable 0-200 ohm potentiometer/rheostat, verified its accuracy with my DVOM, and substituted it (outside the tank) for the sender in the tank. The readings it gave as noted in my earlier post, indicated MY gas gauge (maybe not yours or other's) requires OVER 200 ohms in order to bring the gas gauge needle to "empty". Thirty ohms only brought the gauge down to 3/4-full. That was the basis for my 0-200 needed ohms-range, and the realization that of the half-dozen or so senders on the market, none had those ohms ratings.......suggesting that the gas GAUGE was defective, thus my search for a replacement gauge. (I included a photo of the rheostat...... you can see the windings; just like those on a fuel sender.... makes a handy external substitute). Am I still missing something here????? Bill.