Chevrolet Repair: 98 malibu, fuel pump relay, electricity problem

Question
My 98 Malibu(4 cyl) can't start. When I turn the electricity on, the fuel pump relay switches on and off quickly, making a lot of noise, while the fuel pump doesn't work. Replaced the relay, the problem remains but the sound of relay switching stops after around 5 seconds. A lot of lights (ABS, battery, theft, engine) are on and the gear indicator turns off when I turn the electricity on. All these problems get off if I take the fuel pump relay out, so I guess it's an electricity problem. Could you give me some idea about what the problem is and how I should diagnose? Thank you very much.

Answer
Hi Guo... disconnect the fuel pump at the tank... when you turn on the key you should have power 12volts for 3 seconds on the power side for the pump... if you do and pump doesn't come on, pump is shorting to ground feeding back to the relay.. change the pump....hope this helps... merry christmas