I have just put an engine back in my 95 WRX and on trying to start it for the first time it made a click noise and then all the dash lights went out and I couldn’t try turning it again. After a few minutes the dash lights came back so I tried again but it did the exact same thing. Everything is plugged back in apart from the radiator.

Any ideas what could be causing this

 

this might sound like a daft answer but is the battery fully charged?

 

Check your battery and then all your power cables and grounds....in the engine bay area. Sounds like solenoid is getting power and then when starter tries to drain power theres not enough juice hence the lights go out.

 

Dont no why but its started working now and i didnt touch a thing. Weird.

I had a Power FC running the old engine but have now sold it. Im using the sandard ECU now. Will there be any problems using thhis as i no they fitted a 255 fuel pump and canged the boost. Or will the ECU sort it all out.