Soft_Click
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When I bought my 1966 1200A IH Pickup, the previous owner was running an auxiliary fuel tank out of the bed because the under cab tank was full of rust.
I spent a long time cleaning the rust out, then treating it so it won't rust again (which I've heard isn't a permanent solution). While I did all this, I replaced the fuel sending unit and finished the outside of the tank in cold galvanizing compound which was recommended to me.
I think the cold galvanizing spray means the tank is no longer grounded which may be white my fuel gauge doesn't work.
I wanted to eliminate any possible issues with the existing wiring, so I ran my own wires. (see attached diagram). Basically, the left post is getting 5V power I tapped from the oil pressure gauge, which I know works, and the right side post is getting the line from the fuel sending unit. This is from the perspective facing the back of the gauge.
I swapped out the right side post with a ground wire to make sure the gauge and the 5V line were working, the needle went all the way to full, which I think is a good thing.
When I have it connected to the fuel sending unit, the needle reads empty and doesn't move. I've tried grounding the gas tank by sanding down to bare metal and connecting a wire from the frame to the tank, but that didn't help (photo attached). I also tried running a wire from this little bent piece on top of the fuel sending unit circled in red in the last photo.
After trying to ground the tank both times, I used an ohm reader on the line coming from the fuel sending unit to the gauge against a ground in the cab and it wasn't actually grounded. Also just using an ohm reader on the threaded post of the fuel sending unit to the top plate of the unit read 1 on the ohm reader. I would expect that to be between 0 and 1? I really don't know what I'm doing!
Any advice?
I spent a long time cleaning the rust out, then treating it so it won't rust again (which I've heard isn't a permanent solution). While I did all this, I replaced the fuel sending unit and finished the outside of the tank in cold galvanizing compound which was recommended to me.
I think the cold galvanizing spray means the tank is no longer grounded which may be white my fuel gauge doesn't work.
I wanted to eliminate any possible issues with the existing wiring, so I ran my own wires. (see attached diagram). Basically, the left post is getting 5V power I tapped from the oil pressure gauge, which I know works, and the right side post is getting the line from the fuel sending unit. This is from the perspective facing the back of the gauge.
I swapped out the right side post with a ground wire to make sure the gauge and the 5V line were working, the needle went all the way to full, which I think is a good thing.
When I have it connected to the fuel sending unit, the needle reads empty and doesn't move. I've tried grounding the gas tank by sanding down to bare metal and connecting a wire from the frame to the tank, but that didn't help (photo attached). I also tried running a wire from this little bent piece on top of the fuel sending unit circled in red in the last photo.
After trying to ground the tank both times, I used an ohm reader on the line coming from the fuel sending unit to the gauge against a ground in the cab and it wasn't actually grounded. Also just using an ohm reader on the threaded post of the fuel sending unit to the top plate of the unit read 1 on the ohm reader. I would expect that to be between 0 and 1? I really don't know what I'm doing!
Any advice?
