View Full Version : wacky gas gauge

05-04-2006, 02:49 AM
minor problem when i fill my tank the gauge goes to empty then as it emptys it rises to just over half then begins to go down again. kinda used to it now but sometimes i forget if i got enough fuel.

is it a float in the tank? if it is maybe its twisted, tangled.


05-04-2006, 12:17 PM
Ive Also Got A Wacky Fuel Gauge/float Issue, Fill It To The "top" And It Measures Half To 3/4's . I Have An 8 Gallon Tank. Or Maybe Thats All Ive Ever Been Able To Stuff In, Meaning My Gauge/float Is Really Screwed Up. Guidance Requested Also.................

05-04-2006, 02:06 PM
There is a sending unit in the tank, it's basically a rheostat that gives a resistance value to the gauge depending on fuel level. I would check your wiring first, the sending unit only has 2 wires (red/yellow=12v, black=ground) the ground wire is usually the culprit where it attaches to the tank. If the sending unit is bad, you have to drain and drop the tank, it's in the top of the tank2finger ,a real PITA, but not too difficult. I think a new sending unit goes for about $75, from what I've heard.

05-04-2006, 02:49 PM
You could have also installed the sending unit upside down. I looked at a tintop samurai a while ago with the same problem and the guy was telling me he put the sending unit in upside down. Can you install the sending unit upside down on accident?

05-04-2006, 03:00 PM
never touched it it just started doing it one day. i'll check the ground. but if that dont fix it i can live with it , it still seems to be accurate just wonky.

05-04-2006, 03:05 PM
Hey guys. I'm brand new to the site, and thought I would try a test post. My gauge has been stuck on 1/4 since I bought it. Sounds like a sending unit problem.

05-04-2006, 03:27 PM
where abouts on the tank are these wires?

05-05-2006, 03:02 AM
I think there on the top.

05-07-2006, 04:13 PM
Did Harley Davidson make our gas guages???

05-07-2006, 10:13 PM
Did Harley Davidson make our gas guages???


This is common with the sending unit. If it responds any time during the use of a tank of gas and responds at the same intervals, its usually the sending unit. If it does not respond at all or stay at one level all the time it could be in the wiring, but also could be the sending unit.

For installing the sending unit upside down that guy would have to install it in the bottom of the tank. I would guess he just got his wires crossed....literaly.