Diesel fuel gauge and sender unit, plug location?

For a while not my gauge has been sitting at empty even though the car has diesel in it. I think the sensor may be gone and that this item should fix the issue:

http://ift.tt/1kypey1



(Confirmation would be sweet)



But before buying I would like to double check that the pin-plug isn't just loose. Is this located on top of the fuel tank i.e it will need to be dropped to be inspected?

from the last news http://ift.tt/1hMCWOR

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