Help needed. No start

[rawavr4]

Over the weekend I installed a walbro fuel pump and an adjustable FPR. I got it running today and drove it for a good hour and a half. I come home, park it for a few hours then go back out to start it. I turn the key, the starter engages for half a second, then all power to car car is lost. No crank, no dash lights, no interior lights, nothing. The battery is showing 12.6v right now. I'll be testing each fuse with a test light in a few minutes. I just need some suggestions.

[stealthee]

Check your battery terminal connections.

[rawavr4]

Just did that outside. There's some corrosion on the positive terminal. Must have got there while it was disconnected over the weekend.

[stealthee]

It may have corroded if your alternator wasn't charging for some reason too.

[rawavr4]

I'll test the alternator at work this week just to be sure.