Low fuel light question
- blupupher
- Posts: 575
- Joined: Sun May 17, 2020 5:47 pm
- Location: Katy, Republic of Texas
- Motorcycle: 2002 Goldwing GL1800A
Low fuel light question
So a question on the low fuel light.
Mine does light up, both with the key check (very bright as it should be), and when the fuel is low (around a gallon of gas left, fuel gauge at the low side of the red on the fuel gauge).
The issue I am having is the light is very dim when it comes on when low. I can't see it in bright sunlight, and even on a cloudy day, can't be seen unless I look directly at it.
Is this normal (does it get brighter the lower it gets) or is my low fuel light sensor going bad?
I am usually looking for gas when it comes on, so I have never pushed it past just a few miles from it coming on (the most I have added is 5.78 gallons, and light was still dim).
Mine does light up, both with the key check (very bright as it should be), and when the fuel is low (around a gallon of gas left, fuel gauge at the low side of the red on the fuel gauge).
The issue I am having is the light is very dim when it comes on when low. I can't see it in bright sunlight, and even on a cloudy day, can't be seen unless I look directly at it.
Is this normal (does it get brighter the lower it gets) or is my low fuel light sensor going bad?
I am usually looking for gas when it comes on, so I have never pushed it past just a few miles from it coming on (the most I have added is 5.78 gallons, and light was still dim).
2002 Goldwing GL1800A
- Erdeniz Umman
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Re: Low fuel light question
It should get brighter as the fuel level drops.
- dingdong
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Re: Low fuel light question
Yes that is normal. The sloshing fuel is still cooling the thermister.
- blupupher
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Re: Low fuel light question
OK, was just wanting to make sure the resistor was not going bad or something.
Just seems weird that even with 1/2 gallon of fuel the light still barely visible.
Not a huge deal, as said, my gauge works, and I know my range is in the 150-170 miles if doing all highway (just need to make sure I reset the trip meter every fuel up).
I am thinking of doing an Iron Butt SS1000 this spring, and have been doing some prep rides to see how I feel (only done ~400 miles at one time so far), but getting my range figured out as well as the low fuel light is something I needed to do for sure.
Just seems weird that even with 1/2 gallon of fuel the light still barely visible.
Not a huge deal, as said, my gauge works, and I know my range is in the 150-170 miles if doing all highway (just need to make sure I reset the trip meter every fuel up).
I am thinking of doing an Iron Butt SS1000 this spring, and have been doing some prep rides to see how I feel (only done ~400 miles at one time so far), but getting my range figured out as well as the low fuel light is something I needed to do for sure.
2002 Goldwing GL1800A
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Re: Low fuel light question
Have you made sure that the contacts were all shiny clean?
- blupupher
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Re: Low fuel light question
I have not pulled anything apart to look since I did not know what was or was not normal.
2002 Goldwing GL1800A
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- Posts: 539
- Joined: Thu Mar 26, 2020 4:07 pm
- Location: Northern Nevada
- Motorcycle: 1999 GL1500 50th Anniversary SE
1989 GL1500 FOR SALE
A pack of Super Cubs
Z50A (pre-headlight)
Formerly (in order):
Honda Super Cub (bought 1968, sold ?)
Kawasaki Coyote (early 1970s)
Honda 350 (mid 1970s)
Kawasaki KZ900-PS (1977)
Honda Super Cubs (various years)
Kawasaki KZ1000C (1978)
Kawasaki KZ1000P (various years, 1980 - 2005)
Honda 360 (1983)
BMW R1150RT-P (2001)
BMW R1200RT-P (various years 2007 - 2018, NEVER AGAIN)
Re: Low fuel light question
When you have some time, it would probably be worth pulling the instrument cluster and replacing all of the bulbs. While doing this, check each socket for voltage -- including the ground side. A low voltage will give a dim bulb, and may mean a corroded connection somewhere.
. . .and don't forget to take a look to see that the indicator lenses aren't dirty. It doesn't take much crud to make the lights seem dim.
Motorcycles are highly susceptible to corroded connections, simply because water gets sprayed onto random parts of the harness.
. . .and don't forget to take a look to see that the indicator lenses aren't dirty. It doesn't take much crud to make the lights seem dim.
Motorcycles are highly susceptible to corroded connections, simply because water gets sprayed onto random parts of the harness.
- blupupher
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Re: Low fuel light question
The light is bright during the bulb check with initial key on, just never has gotten bright when it gets low on fuel, just a dim glow.
2002 Goldwing GL1800A
- 4given
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Re: Low fuel light question
Search “Rebuilding Replacement Low Fuel Sensor”. It’s a long post but if you want some background on the low fuel light failure and solutions to the problem you can get lots of info there.
“Fight the fight and do what is right“
- blupupher
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Re: Low fuel light question
I had come across that post and read some, but I don't recall seeing anything about a dim light, just the light not working.
2002 Goldwing GL1800A
- 4given
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Re: Low fuel light question
If you replace the thermal sensor in the tank with a float switch the light will come on bright immediately when you reach low fuel level. A company called Innovative makes a stainless steel switch that works flawlessly. At least it does for me. I got the idea from that post.
“Fight the fight and do what is right“
- DenverWinger
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Re: Low fuel light question
A bit of googling, but here's a link to the switch above.....
https://www.liquidlevel.com/product/sta ... witch-100/
There's a How-To Here on GWDocs for changing the thermister sensor to a float/reed switch sensor from some automotive brake master cylinders. The difficulty with these sensors is in finding a car model where the brake fluid level sensor float actually floats in gasoline instead of brake fluid. Specific car models from the '80's are mentioned as a source for workable sensors, but these cars are getting harder to find in the junkyards.
This sensor says "Float Specific Gravity = 0.50", so that's half the density of water. Gasoline has a specific gravity of about 0.75 depending on temperature and blend, so this should float very nicely!
"Good Find", 4given!, especially considering my low fuel sensor is failing, too.
https://www.liquidlevel.com/product/sta ... witch-100/
There's a How-To Here on GWDocs for changing the thermister sensor to a float/reed switch sensor from some automotive brake master cylinders. The difficulty with these sensors is in finding a car model where the brake fluid level sensor float actually floats in gasoline instead of brake fluid. Specific car models from the '80's are mentioned as a source for workable sensors, but these cars are getting harder to find in the junkyards.
This sensor says "Float Specific Gravity = 0.50", so that's half the density of water. Gasoline has a specific gravity of about 0.75 depending on temperature and blend, so this should float very nicely!
"Good Find", 4given!, especially considering my low fuel sensor is failing, too.
A local inventor has figured a way to turn a sausage grinder backward to manufacture pigs.
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪
~Mark

♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫

♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪

~Mark
- WingAdmin
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Re: Low fuel light question
The topic Building a replacement GL1500 Low fuel sensor details the replacement float sensor and warning circuit that both Virgilmobile and I built.
We used the float from this item:
Amazon - Brake Master Cylinder Cap/Float
You cut the float switch free from the cap, and then fasten the float switch in place of the thermistor.
We used the float from this item:
Amazon - Brake Master Cylinder Cap/Float
You cut the float switch free from the cap, and then fasten the float switch in place of the thermistor.
- 4given
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Re: Low fuel light question
I can’t take any credit other than taking everyone else’s advice. I tried a Honda Civic float but the two I tried only lasted a few months. I’m not sure what I did wrong. I tried a Dorman first and after that one failed, I ordered one from our Local Honda dealer and that failed also. That’s when I discovered Innovation’s product. It’s been working flawlessly since I installed it 5 or 6 months ago.DenverWinger wrote: ↑Fri Nov 27, 2020 9:22 am A bit of googling, but here's a link to the switch above.....
https://www.liquidlevel.com/product/sta ... witch-100/
There's a How-To Here on GWDocs for changing the thermister sensor to a float/reed switch sensor from some automotive brake master cylinders. The difficulty with these sensors is in finding a car model where the brake fluid level sensor float actually floats in gasoline instead of brake fluid. Specific car models from the '80's are mentioned as a source for workable sensors, but these cars are getting harder to find in the junkyards.
This sensor says "Float Specific Gravity = 0.50", so that's half the density of water. Gasoline has a specific gravity of about 0.75 depending on temperature and blend, so this should float very nicely!
"Good Find", 4given!, especially considering my low fuel sensor is failing, too.
“Fight the fight and do what is right“
- 4given
- Posts: 348
- Joined: Fri Jul 17, 2015 6:19 pm
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Re: Low fuel light question
Thanks to Virgil and WingAdmin. And khspe2. These guys are all electronic geniuses compared to me. You are also in that category Denver. I should be paying for all the knowledge I glean from you guys and others on this site.
“Fight the fight and do what is right“
- DenverWinger
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Re: Low fuel light question
The problems with using most Automotive brake cylinder sensors are the floats are very nearly the specific gravity of gasoline and don't float, or they slowly dissolve in gasoline. The Honda Civic sensor is probably one of those.
Scott (WingAdmin) and Virgil have found a good one, their sensors have lasted many years now. I was unaware of (or forgot about
) the availability from Amazon, I thought you had to go "Junkyarding" to find one.
Scott (WingAdmin) and Virgil have found a good one, their sensors have lasted many years now. I was unaware of (or forgot about

A local inventor has figured a way to turn a sausage grinder backward to manufacture pigs.
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪
~Mark

♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫

♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪

~Mark