Another fuel gauge question

[Buckthetruck]

I spent this afternoon reading through several threads on fuel gauges. My gauge sits at empty all the time but drops to a little more empty with the ignition switch turned on. From what I can tell, it seems I may have a hole in the float. Does this sound right? I did a little tweaking with the ground wire but nothing changed. I did notice, though, that I could get the needle to move up a little with a little heavier acceleration. Does this go in line with the hole in the float theory? It is a '65 c10 with the in cab tank. The PO put in a new sending unit and said that the gauge just doesn't work. If I unplug it from the fuse block, it jumps to full. Thanks.
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[jonathan-m]

I would check to see if the sending unit the PO installed is the correct Ohm rating, if it doesn't match the Ohm rating for the gauge you won't get a functional readout.

[Buckthetruck]

Is there any marking on it to tell this or do I have to pull it out and get a meter on it? Thanks
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[jonathan-m]

You'll most likely need to use an Ohm meter to find out, but you don't need to pull the unit. You'll connect the Ohm meter to the wire running from the sending unit to get a reading.

[luvbowties]

Originally Posted by Buckthetruck

I spent this afternoon reading through several threads on fuel gauges. My gauge sits at empty all the time but drops to a little more empty with the ignition switch turned on. From what I can tell, it seems I may have a hole in the float. Does this sound right? I did a little tweaking with the ground wire but nothing changed. I did notice, though, that I could get the needle to move up a little with a little heavier acceleration. Does this go in line with the hole in the float theory? It is a '65 c10 with the in cab tank. The PO put in a new sending unit and said that the gauge just doesn't work. If I unplug it from the fuse block, it jumps to full. Thanks.
Posted via Mobile Device

You asked, "Does this sound right?". Answer is 'YES'. With a hole in the float, it rests on tank bottom all the time, showing a constant fuel level of EMPTY--or very close.

At least your EMPTY-reading portion of the system seems to be operating ok. Now, if you can just get that float to rise with fuel level, it MIGHT show the OTHER levels correctly. *CAUTION: It could have your symptoms with the correct 0-30 ohm sender OR with an incorrect 0-90 ohm sender OR.....see(* below *)

When you remove sender to check float, *check to ensure sender-resistance moves from 0 to 30 ohms*, as you manually swing float arm between its max positions. Also, floats aren't expensive; but they can be successfully soldered when in a pinch or hurry.

Also, you have to pull it out and get a meter on it--gotta pull it out to fix the float anyhow! If it DID have a marking on it, I wouldn't trust it, as the same leftover 'housings' may have been used on the next-year's models.

Also, I have found floats just loose from the swing arm.
HTH'
sam