Conversation Between PRIMERED79 SHORT BED and fmc400

I would go ahead and just replace the float. The float's week spot is where the two halves are soldered together; that's usually where they seep full of gas and sink. If yours requires more patch work; it's more prone to failure and I would just replace.

OK pulled the tank today.
And everything ohmed out like you said, i pulled the sender, and the gauge moves with the arm as i move it.
So sure enough the float (Brass) has two micro cracks in the grove the wire snaps onto.
I have a guy that can braze it for me, but will it crack again you think?

The float is another possibility. Here are the main reasons the gas gauge doesn't work, in order of most common to least common:

1) Ground out at the rear frame is bad - no current through the sending unit and the gauge, so the needle falls all the way to the left (past EMPTY).
2) Bad rheostat (sending unit reads the wrong resistance).
3) Pin hole in float. The float sinks to the bottom of the tank and the gauge permanently reads EMPTY.

I'll have to recheck, but i think i had a ohms reading of 60 when i tested mine.
The thing is, my tank is dang near full, so i wonder if my float is shot?

10 ohms for FULL (float all the way up), 70 ohms for EMPTY (float all the way down).

HI fmc400, i need to ask if you know the ohm readings on the fuel sending unit on a 79 f150 with a 19 gal tank.
I was told one of your post has that information, but I'm having trouble finding it.
Thanks for your help.