Series 2 1963 Fuel Tank Sending Unit

[Fordtootsie]

I went to the web sight listed by loose-electron. The gauge picture matches what a Ser I gauge sending unit looks like. They have a "Ask a question" link so I requested what the ohms readings are for his gauge. I will post the answer when they respond

John in Colorado

 

[Barry]

Do you know if modern gauges like Speedhut that Jerry is using can use either High or Low resistance to indicate Full?

Tom

Tom,

Most of the aftermarket gauge suppliers have gauges for various sender values, but I do not know if a specific gauge can be "switched" by the end-user. I suspect that you have to order the gauge to match the sender.

Barry

 

[loose_electron]

Modern Gauges like the Speedhut require two different resistance values at full and empty. Does not matter if full is the higher/lower resistance and empty is the lower/higher value. What the modern stuff does, it takes the two resistance values and draws a straight line between the two to estimate the tank level.

(In geek speak - the microncontroller in the gauge takes two unrelated end point resistances, and does a linear interpolation between the end points, the resulting transfer relationship is used to interpolate the stepper motor that provides the gauge setting, after passing the values through a low bandwidth averaging algorithm to remove dynamic fluctuations.)

Modern stuff literally has a digital controller in the gauge to average the fuel sloshing out of the equation and do a numeric adaption to estimate the fuel level depending on what the resistance is at the empty and full points.

Classic stuff measures current (the metal strip version of the S4 gauges) or measures voltage division (like the S2) and is pretty dependent on what the actual resistance values are.

 

[loose_electron]

I went to the web sight listed by loose-electron. The gauge picture matches what a Ser I gauge sending unit looks like. They have a "Ask a question" link so I requested what the ohms readings are for his gauge. I will post the answer when they respond

John in Colorado

Hopefully I will have one of their senders later in the week. Ordered on Sunday.

 

[loose_electron]

I have posted several times in the past that the "Stewart-Warner standard" for fuel level senders was widely used in the '60's and '70's. The standard resistance values were 240 ohms empty and 33 ohms full..

They are still in business:
http://www.stewartwarner.com/about-stewart-warner/

 

[Toyanvil]

Got home late, I will check mine tomorrow. I bought my replacement from NOS Locators. Use the cork gasket with "Seal-All" or it will leak, with the stock screws. If you replace the screws, make sure they are the same length.

 

[Toyanvil]

My extra sending is not working I did check my car, with just under a full tank it was 30 ohms. So with a Sunbeam gauge it would be close to empty.

 

[Fordtootsie]

loose-electron

When you get your new sender let us know what the ohms readings are. I have not heard back form this company concerning my information request.

John in Colorado

 

[loose_electron]

loose-electron

When you get your new sender let us know what the ohms readings are. I have not heard back form this company concerning my information request.

John in Colorado

Will do.

 

[Tom H]

Toyanvil, about 30 ohms is what it SHOULD have at near FULL. When the tank is empty the ohms will be about 250 and the gauge will read Empty

 

[loose_electron]

OK, the sending unit from this vendor goes from 51 ohms to 110 ohms over the full range of motion of the float.
The vendor also provides a (cork looking) gasket with the sending unit.

Whether the 51 is full or empty depends on which orientation that you install the sender in.
The hole pattern is such that it could get flipped either way up.
It does look like it will fit the tank opening with the same pattern as the original.

The float arm screws down with a set screw onto the sender, so the length of the float arm can be shortened. (ask the vendor for the long float arm for the Alpine.)
The float arm can also be bent to orient itself to the high and low walls of the tank to account for tipping angles of the sender mount into the tank.

I should be able to make this work with the Speedhut gauge. For this to work properly with original Alpine gauges would probably require some form of adapter circuit.