Fuel Sending Unit???

[89 FXRS]

All of a sudden my fuel gauge on my carburated 2001 Roadglide is bouncing all over the place and was wondering is there a way to check if it's the sending unit or the gauge before having to buy them - (can't return electrical parts) I'm thinking it's the sending unit - even before all this bouncing it wasn't stable like it was when it was new - if I went into a turn the gauge would move quite a bit then after I straightened out the gauge would level out - any ideas???

 

[glider]

More than likely the sender.

Fuel Gauge and Sender Test - Harley Davidson Community

 

[89 FXRS]

replaced the sending unit and no go - any other ideas? maybe the gauge???

 

[NEWHD74FAN]

Interesting, should have been a noisy rheostat, but since you replaced it, use your DMM and check your schematic to see if there is a bad ground connection or pinched wire betwen the sender and meter, then monitor the power source for the meter using your DMM. It should be steady. Check that all your fuses in the block do not have "fur" on the ends, clean and use dielectric grease.

 

[89 FXRS]

More than likely the sender.

Fuel Gauge and Sender Test - Harley Davidson Community

Interesting, should have been a noisy rheostat, but since you replaced it, use your DMM and check your schematic to see if there is a bad ground connection or pinched wire betwen the sender and meter, then monitor the power source for the meter using your DMM. It should be steady. Check that all your fuses in the block do not have "fur" on the ends, clean and use dielectric grease.

OK - I replaced the sending unit and it didn't help - tried tracking it down for bad connection or ground and everything checked out OK - used a friends gauge and it still did the same thing on his -so now I'm lost as to what I should try next - does anyone know what exactly keeps the needle from bouncing around/what stabilizes it???

 

[glider]

Recheck the wiring again and look at any plugs to see if the pins have pulled back out of the plugs partially or if one pin in the plug is a different color than the others indicating a bad connection.