TOPIC:

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For a progressive indication of fuel level change we would need a progressive change in signal corresponding with the fuel level. This is done in most cases with the float type sensor, which provides a change in resistance as the float arm operates a variable resistor. The link you have provided shows for aircrafts a device, where the signal is providing a change in capacitance. As soon as overcapacity changes come into play, you are talking about frequency changes and I don't think I am clever enough to go there. I thought a straight forward change in resistance could be achieved with the thermistors, just as the standard sensor in my tank is operating one light bulb, several should be able to either operate several bulb on different levels or could be used to show a progressive change on a gauge.

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I think the thermistors need to heat up much more so I went and bought another set. I hope they will heat up quicker with lower current going through them.

Wouldn't lower current develop Less Heat?
the big question would be the temp of the fuel, since it constantly changes. there would be a great deal of swing. First from a cold start, of getting a fresh fill from a below ground tank, then as you ride. Park the bike right after a ride, out in the sun on a 90+ degree day, the fuel temp would be quite high. Would your thermistors be up for such a swing? This set on Ebay, do you have the info as to the range for them? Definitely not an covered/ uncovered contact, like a say brake fluid warning switch. If the fuel was conducting then there would be issues with the standard rheostat style sender in nearly every tank out there.
But this has my curiosity going, as I just did 4K miles and my fuel gauge still loves to be unstable.

Yes,you are right lower current will mean less heat. What I meant was that the current in the circuit from battery via the thermsitors (or sensor) via the gauge (or light bulbs) is too low to heat up the thermistors which I bought. So I went and bought thermistors with a lower power rating hoping they will heat up quicker at low current going through them. I tried yesterday but still no luck. I had 5 thermistors in series to start with and the meter in series showed a lower reading than without the thermistors. Of course because the thermistors have a resistance when cold. But the resistance did not change after a while, which means that the current is still too low.

In terms of compensating for the changes in ambient temperature, you are right, this is a problem as well. On my searches on the internet I came across an electronics website and they were discussing the same thing. They than came up with solutions, which where way above my head and at that point I thought I should give up.

I wonder if the low current flow is fixable by adding resistance to the circuit. This works for the LED lights that some have been using for turn signals, with the stock bi-metal flasher unit which needs high current flow to work.
Could you add some resistance, even with a small light bulb and try it? Maybe with a higher draw pulling through them, then at least the one side, getting them to heat up, might work.
What web site did you go to for the issue with the fuel ambient temp discussion?

The current in the circuit is given by I=U/R. U, the voltage is constant (12V) and the more resistance I add the lower the current. I would need to have less resistance to increase the current. I tried this by putting a resistor of 10 Ohm in parallel to all the 5 thermistors, but all it did was all the current flows over the resistor, in fact so much that the resistor got really hot. So if all thermistors in series give the 25 Ohm which I need to get a good reading at lower temperature I would work, but I can not find a thermistor which has about 2.5 to 3 Ohm at 20deg (10 x 2.5 or 3 = 25 or 30 Ohm.
In terms of the web site I looked at, I left the details at work. I get them for you on Monday, but here is one of them.
xrv650story.eu/index.php?option=com_cont...eshootings&Itemid=96

Schorly wrote:

Motor Head wrote: There is a wiring diagram in File Base for your bike, www.kzrider.com/filebase/cat_view/102-19...-kawasaki-kz-1000-m2
i shows the three wires for the Level sensor. Black/ yellow is ground. brown is + ignition switched voltage and the Green/ White is a ground that happens when the switch is closed, Low Fuel. That wire is the one that would be the ground for the warning light, with one side of the bulb hot from the Brown wire, and the Green/ White providing the ground when Fuel is Low.

So I understand the switch in the tank is grounding the warning light. What is the self checker doing?

I had this same question the other day and came across this post, and one other, but no answer here. I did a little research online and found that what it does, is run a self check on your warning lights. In other words, it turns them on for a few seconds when you turn the power on and start your bike, similar to the check engine light on your car. It MAY also alert you to burned out bulbs, or bad circuits as well, but I'm not sure I trusted that part of what I found online. I would consider this part a "cosmetic" one, not a necessary one.

~Clutch

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Have you gotten anywhere with this?
Bump,

No, I am a bit stuck now. I tried the smaller sized thermistors hoping they will heat up sufficient at low current, but they don't. I need to understand how the one single thermistor in the low level fuel sensor gets hot. I think it has something to do with the low level check switch, which is not working properly on my bike (I think) so I have purchased a replacement switch, which I got the other day.
So I am searching the net trying to find anybody explaining how this switch works:


The Kawasaki part No is 27010-1015