I'm having problems with this bass i jus got?

Ok, so i just got this bass. Through a friend, who's friend left it when he moved out of the appt they were sharing.

After i got it, this thing was beat up terribly. But atm i had to sell my 2 bass' a few months earlier and so i been missing playing. Anyways, after getting it, the strings were terrible, completely worn, so i changed them. He couldn't find the cord, so i had to buy one.

Now, i get all the stuff cleaned, (it looked like he spilled some drink on it or something)

I plug it into the amp that came with it, and nothing.

I plug it into my electric tuner, and the tuner recognized the input of the bass and allowed me to tune it.

Mess with the connections, messed with everything...and nothin. So finally getting frusterated i took the pickguard off. Underneath i didn't find any signs of water damage to the electrics. I took the pickups off.

The amp seems to have no issues as i can tell (of course i can't plug anything into it, to be 100% sure). But when plugging / unplugging while its on, it makes the usual sound it should in all the amps i've had, they've all done this, so it leads me to believe its not an issue there.

While the pickups and plug were still wired to the pickguard, i (by hand) ran the pickups over the strings, and the amp began making this extreme static sound.

Now, from the facts provided, can anyone tell me, is the amp bad...or are the pickups just gone and need to be replaced.

I'm broke atm so, i need to know which side of the road to go down and i can't be wrong, cuz if i am, i won't have money to change my mind later. Also i don't have any other instruments in the house to test the amp unfortunatly.

Also, i'd just place to make a PSA here...if you don't want to take care of your instruments you should not own them...this bass i got is shameful how he treated it...and while its jus a Fender Squire, ITS STILL A BASS DAMMIT!