Car won't start , no dash light or electrical ! Please help 1st rebuild
 

2000 Honda Civic ex coup
Rebuilt D16Y8 stock motor

So I wired everything up and then I hooked up my battery when I try to jump it the horn started blaring so I went and charged my battery and also got new terminals plug it up again and still no lights dash Lights or electrical... I'm assuming I wired something wrong what is common? I also removed the horn fuse. My knock sensor is broken , my AC electrical connection is broken... And I'm not sure if I got a extra wire or not. There's 2 big connectors that look block off for auto or something .

Re: Car won't start , no dash light or electrical ! Please help 1st rebuild
 

...if you rebuilt an engine why did you change any wring?

Also what did you change?

...why is the horn turning on?

It sounds like instead of power going to the ignition circuit, it is going through the horn circuit.

Re: Car won't start , no dash light or electrical ! Please help 1st rebuild
 

Trace and measure positive side from battery to fusebox to ignition switch. Somewhere the power got lost, bad connection.
Same goes for the ground side, if you don't find a problem on the positive side.

Blown main 80A fuse? Other fuses?

What electrical items in the car DO work?