Fuel tank level sender?

[SLR No.77]

Does anyone know what the resistance rating of the fuel tank level sender is? I'm thinking about fitting a programmable Stack fuel gauge

 

Stu.

[zetec]

Cool

 

Ive just done the same & my stack gauge now works in reverse

 

Very interested in this thread- please help

[aerobod - near CYYC]

Here is the calibration I measured on my 2012 R400 tank sender, first column is litres in tank, second is resistance in ohms, third column is total resistance with 667 ohms in parallel (1000 and 500 ohm resistance in parallel to try to match Caerbont gauge range). Note that the sloping bottom on the tank causes the standard sender to hit the bottom with between 6 and 8 litres remaining:

 

0 195 150

2 195 150

4 195 150

6 195 150

8 169 135

10 158 129

12 128 109

14 107 92

16 81 72

18 71 64

20 61 54

22 49 46

24 43 40

26 34 32

28 25 24

30 21 20

32 16 16

34 14 13

36 9 9

[SLR No.77]

These are the options for the selection of "standard" sensors for use with the 52mm Stack fuel gauge. It's not entirely clear from the manual (here) whether the first resistance figure is the resistance at empty but I assume so:

 

73 - 10 ohms

16 - 158 ohms

0 - 30 ohms

0 - 90 ohms

240 - 33 ohms

107.5 - 7 ohms

131 -12 ohms

 

I assume either of the last 2 options could be used with an appropriate resistor to alter the scaling?

 

Stu.

[zetec]

so what do we use from the above list?

 

Is it 16-158 ohm?

[SLR No.77]

Anyone?

[Paul Deslandes]

Hi Stu

 

using Aerobod's method and calibration data, select 16 - 158 Ohm and wire an 820 Ohm resistor in parallel with the sender. This should track fairly well and be at its best when close to empty, which I guess is when you really need it to be accurate.

 

How's the steering wheel control going?

 

Paul

[Paul Deslandes]

I've just had a quick peek at the manual and there's a custom calibration mode at the end. It requires you to start with an empty tank and then for you to fill it up but you should be able to get close by removing the sender and setting it to the (nearly) empty and then full positions. Using this you shouldn't need any external resistors.

 

Paul

[SLR No.77]

Hi Paul The current gauge (excuse the pun!) is in another owner's car, if we can get this one working properly I'll fit one in mine - the Stack analogue gauges are far better quality than the Caterham/Caerbont offerings and still quite inexpensive.

Using the custom mode it can be calibrated fine but as soon as the ignition is turned off it loses it's setting .... I'm thinking if it's possible to work with one of the 8 standard modes it will be better in the long run.

 

Off topic ... the steering wheel control is working well, I've now received the extra switches/relays/connectors etc and I'm starting to assemble the additional functions. I'll give you a shout when I get to a worthwhile stage

 

Stu.

[Paul Deslandes]

Are you sure it loses its calibration if its switched off? I can't believe that they'd sell a product with that limitation. If it really does work like that, you could leave the gauge connected to the battery so it remembered its settings - can't use enough juice to drain the battery - and use the parallel resistor/ 16 - 158 Ohm setting as a fall back.

The manual isn't clear but it doesn't say you have to calibrate it every time which I would find really surprising.

 

O/T I now have a Classic version which will work with both pos and neg earth vehicles.

[zetec]

my stack fuel gauge when ign off shows level

[Roger Ford]

Quoting Aerobod: 

third column is total resistance with 667 ohms in parallel (1000 and 500 ohm resistance in parallel ... ).

That would be 333 ohms, not 667 ohms.

 

 

[Paul Deslandes]

well spotted Roger 😬