Fuel sending question

[boondocker]

Ok, this is probably a dumb question but oh well. I put a new gas tank in my WC, I used the same sending unit, it worked fine in the old tank, now it’s pinned on full??? I only put 5 gallons in it. It’s only one wire, and I made sure the float wasn’t hitting any baffles when I put it in. I don’t know what went wrong. Any insight would be much appreciated.
Thanks
Dean

[Gordon_M]

The fuel gauge works by earthing, and sensing resistance to earth. If everything was working, and now it is showing full, somehow the sender unit is showing a full earth value.

Disconnect gauge at tank, reading should drop to empty, then earth the gauge lead to the chassis and it'll show full again. That will pin it down to an extra unwanted path to earth somewhere in the gauge sender, usually the insulation on the terminal to the gauge body.

[boondocker]

Thanks Gordon, unfortunately for me the only way to check the wire is to remove the tank again, I’m really not up for that again at this time. It took everything I had to get it back in. Guess maybe I should have checked that before I put
it in. Learning curve I’m working outside on a piece of plywood.

[Gordon_M]

OK, many WC's have a cover plate for the sender to allow access, but maybe not yours. It'll be a sender permanent earth fault I think.

[boondocker]

No cover plate for me, I don’t get that lucky thanks, wonder if I could add one

[Dozerman51]

What model Wc do you have?

[boondocker]

It’s a 42 WC-51

[beepbeep]

No cover plate for me, I don’t get that lucky thanks, wonder if I could add one

Worth doing if you don't mind cutting into, what I'm assuming is, the original wood floor. Mine is ex Norwegian Army with a steel floor replacement and a cover plate, I can get you a photo with dimensions if you want

Chris