The lights went down and there are no dash lights?

Okay guys, you've been with me to this entire motor installation. Change the motor got that done and all hooked up. You guys help me with the starter problem, got that fixed. Got the motor freed up to where it spins like a dream. Fix the wiring for the battery hold on yards motor cranked finally. So, I was like awesome. So, once I got the motor free and I realized it would crank from the key I can turn the key and it cranked I was like yes. So, I put the breather back on plugged it in hooked the belt back up, hooked up the spark plugs. I got in turn the key on everything lit up everything's fine, as soon as I went to turn it to crank it all of a sudden it started it immediately started crank and clicked and then the lights went down and there's no dash lights turn the key on the fuel pump don't kick in there's no dash lights there's no nothing the radio comes on if you open the door the lights come on so there's power to the battery but when you turn the key other than auxiliary nothing happens what did I do where did I mess up.