Fuel Gauge problems

[alba123]

I'm swaping in a 1kzt and the full wiring loom. The fuel sender and fuel gauge were working perfectly fine before I removed them. I've put in the wiring loom into my truck and went to test the sender/gauge. When I plug it in, the gauge goes straight up to full. When the fuel sender is unplugged the gauge stays. I've tried grounding the positive wire and nothing happens. I also tried pluging into another working fuel sender(they both worked perfectly fine) and the reaction is the same.
Can anyone suggest any test I can do to figure out what is wrong? or any other possibilities of what is wrong?

[sam333]

Your fuel gauge works just like an ammeter the more current it passes, the higher the reading will be. Your sender is a variable resistor , the higher the fuel level, the more current it passes to ground( and pulls through your gauge/ ammeter) the higher the reading will be. You have a short somewhere between the gauge and the sender. If you disconnect the wire at the sender and the gauge drops then you have a short to ground in the sender itself. If it does not drop then you have a short somewhere up the line.

[alba123]

Well nothings happens with the gauge when the sender isnt connected. Only when the sender is pluged in does the gauge move....straight to full. So if it is a short in the wiring, is there any trick to figure out where?