Fuel pump relay

In one of the fuse boxes under the hood. Owner's manual and inside of the box cover might tell you which one. Also try Googling it.

Where is my fuel pump relay switch on a 1997mercury

Either in a box to the right front of the engine compartment, or middle of the left side. Do you have an owner's manual? It tells one.

No sir i dont have one i just bought the car.and i put a brand new fuel pump in it.and drove it for two days..now when i try to start it the fuel pump is not coming now.what do you think it is

I still say replace fuel pump relay, in black box right front engine compartment. Pull the cover, it will way inside which one. Standard relay, they're all the same. you could swap two, just to see. Can be bought on amazon, or any auto store. I bought mine from amazon, just typing in the number on the relay.

When I have more time, i could look in my '98 manual, but I'm off to the doctor right now.