2000 fuel gauge or sending unit problem ?

[rigid]

2000 suburban . Had a new fuel pump module , which includes sending unit replaced at GM dealership lifetime warranty if done at the dealer . less than a year later gauge starts dropping and reading empty . Does this a few times and has been like that since . How do I determine if it is the gauge or the sending unit ?
Stealership and Gm say the new sending unit was not the pump so it is not covered . Their contention was that the pump still works .
Thank you

[truckdude239]

way i look it it is the sending unit is part fo the pump so should be covered never heard of them giving a lifetime warranty though

[rigid]

At the time we were on vacation towing a camper . Made it to a dealership sputtering along for 12 miles . It died for good in the lot while I was inside talking to them . I knew it had gotten a new before we bought it . They ask if it was a gm pump because it would have a lifetime warranty . I called previous owner and my luck it was not .
$1400 dollars later I had a new GM pump module and a lifetime warranty that does not cover the sending unit apparently . Gm said they would back the pump , but not sending unit .