I have been having fuel gauge issues for the past couple of years, and it’s time to tackle them! When my fuel gets to about 3/4 tank, my fuel gauge begins to bobble from full to 1/4 tank (moving back and forth without reason). Once my fuel level gets down to about 1/4 tank, the gauge settles down again. I am guessing that it has to do with a faulty fuel float? I haven’t seen any related videos, but I may be looking in the wrong area. I’d like to properly diagnose and then replace/repair the effected part.
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Please review these videos to get an idea of the potential issues.
Related Fix My Hog Videos:
https://www.fixmyhog.com/video/harley-fuel-pump-filter-removal-005103/
Have more questions? Check out our Q&A index page to find some answers.
I have a 06 Ultra Classic the fuel gauge does not work.
Hi David. First inspect the gauge’s plugged connection below the left side of your fuel tank. The plug is black with three wires: orange, black, & yellow.
Make sure that the plugged connection us secure. Verify that you have voltage at the orange wire and that the black wire is grounded.
Most commonly, it is the fuel sending unit, inside the fuel tank, that fails.
If the gauge plug checks out, you will find yourself inside your fuel tank to repair the issue.
https://www.fixmyhog.com/video/harley-davidson-fuel-gauge-removal-and-replacement-008425/
https://www.fixmyhog.com/video/simplifying-electricity-002170/
https://www.fixmyhog.com/videos/electrical/
Thanks
Mark-FMH
I have a 2010 Ultra trike,my fuel gage stopped work while having voltage regulator issue !!! Any help would be great .
Hi Richard. I have never seen the two issues related.
Most commonly, the fuel sending unit inside the fuel tank fails.
First inspect your fuel gauge plug on the lower left side of your fuel tank.
It is a black plug with 3 wires: orange, black, & yellow.
Verify that the orange wire is powered.
The black wire should be grounded.
If that plug checks out, you will need to replace your sending unit inside the fuel tank.
https://www.fixmyhog.com/video/harley-davidson-fuel-gauge-removal-and-replacement-008425/
https://www.fixmyhog.com/video/harley-fuel-filter-removal-on-a-softail-or-dyna-008005/
https://www.fixmyhog.com/video/harley-fuel-filter-install-on-a-softail-or-dyna-008007/
Thanks
Mark-FMH
I have the same issue with my 2005 Ultra!
Try some Chevron Techron Concentrate (Black Bottle) available at auto parts stores and Wal-Mart. BMW riders with float type senders having been using for years. Mix about double the ratio whenever you can leave in the tank for a while. It removes the contamination on the windings of the float switch that the wiper contacts. Also works great on car float senders. Just used on my 2010 Scion with 120,000 miles where sender went intermittent. Took about 5 tanks to clear up the problem. Cheap fix and works great.
I’ve a 2004 FXSTI standard softail I put a new speed sensor. My speedometer is still pegging out weather I sit there and idel or ride what causes this?
Hi Bob. Sounds like a bad speedometer.
You already ruled out the speed sensor.
The only other thing we would suggest is closely inspecting all related speedo & speed sensor harness & plugged connections.
https://www.fixmyhog.com/videos/electrical/
https://www.fixmyhog.com/video/simplifying-electricity-002170/
https://www.fixmyhog.com/product/overview-of-electrical-systems-part-1-download/
Thanks
Mark-FMH
2000 ultra fuel gage reading empty
Hi Tim. It is very common for the fuel sending unit, inside the fuel tank, to fail.
First, however, verify that the gauge is securely plugged in on the lower, left side, of the fuel tank.
The plug has 3 wires. Orange, black, & yellow. You can also verify that the orange wire is powered and the black wire is grounded.
https://www.fixmyhog.com/video/harley-davidson-fuel-gauge-removal-and-replacement-008425/
https://www.fixmyhog.com/video/simplifying-electricity-002170/
Thanks
Mark-FMH
I have a 2005 Deluxe and the fuel gauge is always pinned at full. Plug is good wires all good. Little help would be great. Thanks.
Hi Don. Sounds like you either have a bad sending unit or your float is stuck.
Would suggest getting inside your fuel tank to inspect your float. You may not need to completely remove your fuel pump assembly to move your float.
Try reaching in with a long screwdriver to see if you can get the gauge to move.
If moving the float does not change your gauge position, you are most likely in need of a replacement sending unit.
https://www.fixmyhog.com/video/harley-fuel-filter-removal-on-a-softail-or-dyna-008005/
https://www.fixmyhog.com/video/harley-fuel-filter-install-on-a-softail-or-dyna-008007/
Thanks
Mark-FMH
I have an 05 Softail Fatboy. My fuel gauge is stuck on “full” all the time. I watched a video on replacing the fuel gauge and I did the swap but my fuel gauge is still stuck on “full” even though I have half a tank? What’s next please?
You will need to replace the fuel sending unit.
https://www.fixmyhog.com/video/harley-fuel-filter-removal-on-a-softail-or-dyna-008005/
https://www.fixmyhog.com/video/welcome-to-fix-my-hog-site-review-008131/
-Mark