Bought my bike used and on the way home found that the halfway mark on the fuel gauge means that I have enough gas to get half-way home. Wound up on the side of the road with a dry tank, so the half way mark on the gauge actually means empty.

Pulled the sending unit from the tank and measured 85 ohms with the float low and 12 ohms with it high. Can anyone tell me if this is reasonably close to spec?

I hoping so...local dealer says a new one is $225.

I use my the trip meter as the last word as to when its time to fuel up, but I figure that if since the gauge is there it might as well work right.

 

My '03 has been that way since new. It will run over 100 miles on 1/2 tank then the gauge seems to drop every mile. Fuel injected so I have a light for low fuel. Low light means i have no more than 25 miles left in the tank. I usually jsut watch the trip meter. In town normal = 150 miles, Bar hopping all out = 125 miles, and if your feeling lucky highway is somewhere between 175 and 225 miles

 

My fuel light is out of whack too and that makes sense as it uses the same reference as the gauge. I rely on the trip meter, its just an irritation to have something right in front of me that doesn't work right. I'm stripping the bike down for new paint, and figured that since I had the tank off it might be a good time to fix it....if it can be fixed.

 

Testing sender and gauge.

1.Ground Y/W wire of fuel gauge sender. Turn ignition switch ON.
Fuel gauge must indicate FULL. If gauge indicated FULL, gauge is functioning correctly. Proceed to step 2.
If gauge did not indicate FULL, proceed to step 3.
2. Set MULTI-METER (Part No. HD-35500) to measure the resistance of the sending unit. Place one probe on Y/W and the other probe on a good ground.
a. If fuel tank is full, the reading should be 40 ohms. An empty tank should have a 240 ohm resistance. A half full tank will be approximately 97-118 ohms.
b. If a very high resistance or infinity is indicated on the meter, the sender may be “open” or not grounded.
Check that sender and fuel tank are grounded by placing one probe of Multi-Meter on sender flange and the other probe on crankcase. Meter must indicate one ohm or less. Replace sender if one ohm or less was present. If a higher resistance is present, check for poor connection on ground wire.
3. Check voltage to O/W (+) and BK (-) wire of fuel gauge connector [117] if gauge did not indicate FULL.
a. Correct reading is equivalent to battery voltage.
b. If battery voltage is not present check for broken or disconnected wire. Replace gauge if wiring problem is not found.

 

I found this info for my FLHTCUI. Looks like my sending unit is reasonably close to normal. If so I think the float might be hanging up on the side of the tank. It's kind of a tight fit.




3. The meter must indicate approximately 7-95 ohms on FLHT/C/U and FLTR models, 27-260 ohms on FLHR/C models.
a. If the fuel tank is full, the reading should be approximately 7-14 ohms on FLHT/C/U and FLTR models, 27-40 ohms on FLHR/C models.
b. An empty tank should have a 74-95 ohm resistance on FLHT/C/U and FLTR models, 240-260 ohm resistance on FLHR/C models.

 

got that out of an 04 FLHRI service manual. should be same tank and sending unit.

 

Don't know why I didn't think of this earlier...maybe because I had the bike all stripped down.

Put the battery back in, found the connector that went to the tank. Hooked it back up and let the sending unit (now removed from the tank) float sit at it lowest position. Fuel gauge went to E. raised the float to its highest position and gauge went to F. Held the float about half way up and the gauge read 1/2.

Looks like the float was hanging up on the side of the tank, since before the gauge would go to about 1/2 and then stay there. From 1/2 to full it worked fine.

When I put the sending unit back in for good ill use a stiff wire to pull the float though its range. If it hangs maybe a little tweaking of the float rod will get it positioned where it'll move freely.

 

I know I'm a tad late to the game but thanks for the info. I'm having the same issues with my '07 FLHX. Pulled the sending unit and tested the float yesterday. It was registering changes in ohms when manipulated but I didn't find this post until today so I didn't know what range it should've been in. I will go back and check later using this as a reference. Pretty certain it's faulty. Any way to replace just the float and circuit board, or do you have to replace the entire unit including the pump?

 

This happened on my bike. I bent the rod that the float is connected to in order to make it more accurate. It worked well. This was for an 06 FLHR.