"Any ideas where should i start.?"

KISS is for "keep it stupid simple."

No need to crank or try to start the car, right?

Here's where you start when the rain abates:

Pull the electrical plugs from the air mass meter, idle air control, all four of the fuel injectors on the rail, and the fifth fuel injector under the intake manifold. Lift the rear bench seat and disconnect the plug on the yellow wire there. Remove the #4 fuse from the interior fuse panel.

Now put a new fuse in at the battery. Turn the key to KP-2 (no need to crank the engine) and repeat this after putting every item disconnected above back one at a time until the fuse blows again, starting with #4 fuse.

If it still blows with all those things disconnected, most likely there's short circuit caused by someone working on the car who has made a mistake. Some mistakes others have made are using the wrong fuel relay, the wrong air mass meter, pinching a wire while installing a radio, etc.

Some things you may want to convey to us as you go: Wagon or sedan? Is AMM a -016? Is ECU a -561?
--
Art Benstein near Baltimore

Flowers leave some of their fragrance in the hand that bestows them. -Ancient Chinese Proverb