Hi all, I’ve just bought a 2006 1100 Griso and discovered the low fuel light doesn’t work. Looking at the parts diagram, the sensor doesn’t seem to be listed separately.
Has anyone replaced it on theirs? Any help, ideas and tips appreciated.
Thanks.
I am pretty certain that it is part of the pump assembly in the base of the tank. If you are taking that out be prepared to replace the fuel filter (some are plastic and swell and burst) and the internal hose to the pump (some are not rated for fuel immersion swell and fall off- seriously!!).
PS you have nylon fuel tank do not use e10 or higher.
Lots of information on GRiSO ghetto.
enjoy Jon
1 Like
The component in question is that cylindrical thingy, a thermistor, under the loop of the orange wire in the picture from Brian.
Assuming the bulb and wiring are sound then most likely the thermistor has blown.
Inside that cylinder is a thermistor connected to the input wire at one end and the other end to the cylinder body, with appropriate insulation.
Whilst there is fuel in the tank to absorb electrical heat, the thermistor maintains a high resistance thereby breaking the circuit. As fuel level drops, less fuel to absorb the heat so the resistance reduces allowing the lamp to illuminate.
I repaired mine when I wanted to reduce the level at which the light illuminated. I’ve got it down to around 5 litres now. It used to come on when there was still half a tank of fuel!
If you’re interested, I’ll try to find my notes an the thermistors. Cost me pennies for five of them. A case of postage greater than the items.
1 Like
Hi Jon, thanks for that. I’ve been reading on Guzzitech about the need for metal filters and changing the pipe.
There’s just so much more to go wrong on modern bikes compared to ‘proper’ bikes of the ‘70s and 80s!
1 Like
Have you checked the bulbs - I replaced all my ones for LED T5.
My 2005 California EV Fuel Level Sensor has gone as well trying to get a replacement is like gold dust no luck yet tried several outlets even in Holland and Germany price 160 Euros (PHEW).
Fuel level sensor ev, bassa, special €166,54
SKU: 031030000000
Alternative SKU: GU03103000
Thanks Brian, it’s good to see what’s actually inside and what I’m looking for.
Thanks for the info, really useful, especially as I can’t find the original part listed anyway.
5L in reserve seems far too much, I’d have thought half that would be ample.
Yes please, any details you have would be really helpful. 
Thanks Richard, the bulb lights on the ignition on check so it seems like the sensor has gone. From searches it seems it’s not that uncommon.
Traced old invoice.
Bought 5 x 1k Ohm thermistors for £4.58 delivered. Blew one when playing, another lost to over zealous soldering, one fitted last April and the remaining two were put in a safe place for future use. If only I could remember that safe place 
The difficulty for me is/was getting the pump assembly out of the tank. There’s a knack to getting the right angle and twisting it out through the tank.
Thanks again for the info. I’ll have a look for them. I’m guessing the mounting height can be altered at the same time to change the amount in reserve? Only issue is, I haven’t had the bike long and the light has never worked, so I don’t know what mileage was actually left once it came on.
I believe the manual says almost 3/4 of a gallon so maybe 30-40 miles?
Hi Gussitano I have the same problem with my 2007 Griso. Can you be more specific with regard to the thermistors as when I look for these these come in many shapes and sizes. Thanks.
Hi Tzindo, hopefully he will as I’m also slightly baffled by the choice and struggling to find a metal bodied one but I believe it will need to be NTC.
Not sure if this will help, it talks about a reed switch rather than a thermistor
https://dpguzzi.com/reed.htm
Thanks for that Don, very interesting and could be a cheap solution. Would need to think of a way to activate it, some sort of tilting magnet maybe? Helped by the tank being plastic too.
Hi guys,
The thermistor is inside that cylinder which itself is soldered onto the mounting bracket. Thermistor is about 3mm long with a connection tail at each end. The feed wire from the wiring loom / plug connects to one tail, insulated from the cylinder and the other tail pokes through a small hole at the base of the cylinder and then soldered.
Here’s a couple of pictures.
I am not connected in any way whatsoever with the retailer.
I had to unsolder the cylinder ‘holder’ from its mounting bracket. Then carefully prised open the crimp of the cylinder which is folded over the insulation cap. Less damage the better as you need to reassemble / crimp. Inside I found the thermistor with a broken tail which proved the open circuit. Still unclear as to what caused the break. Then I bent the tails North and South to reach the input wire and poke through the hole at the base of the cylinder. Once suitably bent and cut to length, I fed the input wire through the insulating cap, soldered one tail of the thermistor to the input wire, poked the other tail through the base of the cylinder, trimmed it and soldered from the outside.
Then in my excitement I rigged up a temporary circuit to test and yep you guessed it went POP!!! Well I did by 5 units.
Repeated the process.
Then did the test rig again. This time immersed in a jug of petrol. It gave me an opportunity to research read and learn that petrol is not conductive to electricity. I did not know that. The test proved all good and so it was remounted onto the bracket which I had repositioned a little lower.
Very satisfying. Have you seen the cost of the replacement part?
1 Like
I would assume this for the on / off warning light device rather than a fuel guage.
1 Like
Thanks for the detailed fix including thermistor part number. The oem unit is expensive. So this looks a very good option. For my Griso the yellow warning light shows when all idiot lights illuminate at ignition key cycle. From experience and running out of fuel with no warning light informing me of low fuel, this is a necessaity. BTW I do set the trip to record milliage at fill up but this was reset when I had to remove the main battery to work on another aspect of the Griso. Thanks again for the fix and how to guide.
1 Like
Omitted to say that the NTC bit is important. It defines the operational direction of the thermistor.
This is an extract from Wikipedia:
Thermistors are categorized based on their conduction models. Negative-temperature-coefficient (NTC) thermistors have less resistance at higher temperatures, while positive-temperature-coefficient (PTC) thermistors have more resistance at higher temperatures.