Just replaced the battery in my 03 acura and the horn goes on and stays on. theres absolutely no power and the car won't start

https://straighttalkautomotive.com/OBD1/nissan-OBD-I.html

Always - to + go to forums

Was the battery boosted recently or hooked up wrong? Check fuse relay center close to battery for blown fuses.

Sounds like a anti theft. Put your key in the ignition but not in the start. just put it in. See if you can remove the battery now without the horn going off. If you can also find the horn and un hook it. there should be a connection clip if you trace the wire down.

Hope that helps
Dan

horn relay located on the right side kick panel,you will see a row of relays,if horn relay is okay, more likely your horn control pad has a short inside causing horn button contacts to stick causing horn to keep blowing.

the battery wont stay charged? if youre putting in a fully charged battery and your car runs, but then the battery slowly dies, the problem will be your alternator. the alternator is what maintains a car batteries charge. try replacing the alternator. hope this helps.

u shud scan vehicle 1st--a flaw in the wiring harness may be present or solenoids etc cud be staying on--go in engine area and chec the maxifuses that connect to alternator-if burnt then batt wouldnt charge--secure a repair manual

Absolutely - You'll find it in the main fuse-box - probably located in one of the kickpanels (near your feet) or dashboard cover, or maybe even in the glovebox - There will be a fuse that feeds a horn relay - the ground side is fed from the horn pad, and the output side fed to the horn itself (engine compartment). The fuse for the horn is located in a fusebox with about another 25 fuses; and should be hot at all times, both sides.