Fuel pump light coming on!

98' Dodge Caravan 3.0L. The Fuel pump light keeps dinging on and off, but I have plenty of gas? Any suggestions please.

its the same symptoms on my grand caravan 97 3.8L ... Low fuel light and chime dings when the tank is between 3/4 and full. fuel gauge also starts to drop for an instant when the chime dings and sometimes the gauge reads to empty when tank is full.
Please anyone help me..
Thanks in advance..
Armando

The sending unit is probably going in both cases.

Thank you for your quick answer .. but what do you call "sending unit" .. I appreciate your help...
Syncerely

Yes thanks for the quick answer. My light does exactly the same as canon 1's. I would also like to know about the "sending unit". I'll call a shop today or await your response.

Sending unit is in the tank.

Thanks for the reply. That sounds like too much money. I'll let it ding.

Verified !!!! .. under 3/4 of the fuel tank .. the light and chime ding ..go off .. an returns when teh fuel tank is full..