Help needed figuring out fuel level electrics

[stewgnu]

Hey up All,

I'm stumped.

I've not had any low-fuel indication since replacing my broken ITI clocks with a koso unit.

So, I replaced the thermistor assembly (2004 ballabio). I noted the 2 sender wires were yellow/white and black from the tank end. So i hooked up the Yell/Whi wire at the front to a bulb unit, and earthed it, but i'm still not getting anything. I had assumed it was fairly straightforward...

Can anyone illuminate here? KRoy?? I still don't know if the old thermistor was faulty or not...

 

Using the trip meter + manual, visual peeks into the tank for fill-ups at the mo.

 

Stew

[Steve S]

Stew, the thermistor completes the earthing of the bulb so you will need a 12v feed to one side of the bulb and the other side of the bulb to the thermistor wire that is not earthed, ignore me if you have already tried this

[Kiwi_Roy]

Steve's correct the lamp draw is important also, an LED doesn't draw enough. Post a link to the dash you have and I will see if I can. make sense of it.

 

 

Sent from my shoe phone!

[stewgnu]

Cheers guys, i just need to hook up a small barnacle bulb, will have another look..

[buellish1]

Stew,I must be blind,I posted my own low fuel light/sensor thread and had I just opened my eyes I would have seen yours.Having replaced yours could you tell me where it attaches on the fuel pump unit?I attached an image to the thread below.

 

http://www.v11lemans.com/forums/index.php?showtopic=19477

[stewgnu]

Hooray, once more i have a low fuel light! Cheers Steve + Roy.

Now if i could just make the bulb visible in daylight... :-/

[Kiwi_Roy]

I have LEDs on mine, they are visible in bright sunlight, the fuel level is a special case, it needs the load the original lamp provides.

I soldered an old lamp in parallel and tucked it out of sight.

 

Others have complained the LEDs are too bright at night, you can take care of that by having a Day/Night Voltage setting on the lamp supply

 

 

https://www.superbrightleds.com

Look for type 194

https://www.superbrightleds.com/search/led-products/wled-g-90/

WLED-x-90      x = colour to match the filter 

The nice thing about this particular lamp is it's AC/DC so you don't have to worry about polarity

Don't use lamp-holders just solder the wires right to the lamp.

[stewgnu]

That's a great solution. This is the unit i have installed- all the idiot lights are set into the face itself, except the low fuel indictor as i don't think our sender system is compatible. Hence my routing to a separate bulb set into the back of the headlamp:

https://www.google.co.uk/search?q=koso+cafe+combined&newwindow=1&client=safari&channel=ipad_bm&prmd=isvn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi7u8KN0Z_NAhVqDsAKHbVHBR8Q_AUIBygB&biw=1366&bih=928#imgrc=1U9i5xnR2Vt2IM%3A

[footgoose]

KRoy, what is the day/night controller for this? When the old lamp 'for load' burns out, will the led will brighten or go out too? Do you use the holder for this lamp and is polarity a concern for it? What is the primordial ooze you use to encapsulate everything?

 

My soldering set up is much too bulky and temperamental to do this. What do you use for this delicate stuff?

[Kiwi_Roy]

If you lower the Voltage to the lamps they won't be as bright, I don't have this on my bike because I seldom ride at night, I will do a little test and get back.

 

Footgoose,

I just have a pencil iron, I find using a pair of forceps to clamp the wire to the lamp while I solder it helps greatly, melting the wires into the plastic makes it stronger.

 

The old lamp is just soldered to the LED with a couple of short wires. It's very unlikely it will burn out, if it does the LED will come On

 

Not a very good picture but you can see the lamp with it's red leads, glass is covered in white heat shrink.

The little bit of current drawn by the LED is insignificant compared to the incandescent.

 

 

Later as promised, a pair of red LEDs

 

 

The RH one at full 12 Volts

The LH one at around 6 Volts via a pair of 1K resistors as a Voltage divider, it would be very easy to add a switch to have Day / Night setting.

Lamps like the fuel level and flashers not so easy to dim but IMHO they should stay full brightness anyway.

 

I think the High beam and the Neutral lights are the only ones that might need a dimmer the others shouldn't be on, well perhaps the flasher.

[Kiwi_Roy]

Stewgnu.

             The link you posted doesn't specify what you bought. If it's a unit with a digital display it wont work with the normal point level thermistor type, you need a variable resistor type for those.

[stewgnu]

Ah. Erm, well it's a 'Koso Cafe Combined.' Try this link:

http://www.moorespeedracing.co.uk/cafe-racer-guages/koso-combined-gauge-for-cafe-racer.html

Currently building a teeny wee hood to shade my makeshift fuel lamp.

[Kiwi_Roy]

Ok. I went to the Koso Nth America site and downloaded the instructions

It appears you have a model TNT-015

 

http://kosonorthamerica.com/instructions/BA035160.pdf 

 

Section 4-3 describes the fuel gauge. it's designed to work with the float / rheostat type of sender but it will also work with a switch (setting SW)

This could be a float/reed switch like some Guzzi models use or you might be able to get the sensor to pick up a relay instead of the lamp or as well as the lamp. The relay coils are similar in resistance to the lamp when hot, they both draw around 100 mA

 

Do you have an internal or external fuel pump?

[stewgnu]

I've the later in-tank assembly. So are you saying it could be possible to connect thru to the unit after all?

[Kiwi_Roy]

Yes you have a couple of options

 

A/ Fit a reed switch with float and use the SW option.

See MG Cycle part No 29103050 or make your own from a reed, small length of tube, a cork and a tiny magnet.

If you didn't have the in tank pump it's a bit harder to get a switch into the tank thru the small hole where the thermistor fits, option B is ruled out altogether.

 

B/ Get one of the float type sender units to match one of the resistor options 100, 250, 510 or 1200 Ohms and mount it on the pump or cover plate it will light up the 6 segment level displays as the float moves. This would be too cool. Find an old sender at local auto wrecker?