My sending unit works perfectly when out of the tank and I move the float. I have voltage supply, and checked that there are no leaks in the float. But put it back in the tank and it doesn't read again...
Ground issue... Let me re-phrase that...You have a harness/harness plug issue. The orientation changes for the harness once you install it, causing a bad connection.
So you think this is an issue with the plug? When you say orientation do you mean I should flip the plug so it swaps the wires? I guess I am confused on what exactly you think the issue is.
And it still doesn't make sense that it would work outside the tank and not in...I had it grounding out to frame just as if it were in the tank...?
actually it does make sense if you have a bad termination in one of the plugs. Flexing the wires into a new position will create contact. When I used to build and test wiring harnesses we would flex the harnesses on the testers to check for shorts. 90% of the time you find a short in a wiring harness flexing it will cause it to appear and disappear. The goal was to always get it to stop shorting that way we didn't have to rebuild portions of the harness. Which is kind of sad when I think about the fact that a lot of the harnesses we built went into military vehicles.
Makes perfect sense really when the plug is moved or in a differant position then when it is installed in the tank and giving it a temporary "good conncetion" the wires can be corroded and broke inside and look fine on the outside.
The round terminals in that plug are notorious for being loose and not making contact as previously stated. I use a pick to roll the inside of the terminal around slightly to make the fit tighter and a small amount of electrical grease on the contacts to keep water out.
