When you turn the key it is as if electrical system goes to dead short, no starter engagement, all lights dim and nothing happens.
Just changed engines from original to JDM replacement on my 86 Sprint, swapped over the intake/exhaust manifolds and got everything all hooked up but when I went to fire it up I got nothing. Battery power low, bought a new battery and cables no change. Along the way I discovered that my 10 yr old "helper" and friend had pulled all fuses from fuse block, spray painted grille and who knows what else, if he doesn't stop messing with the project I will soon be in trouble with child protective folks..... Anyway I am quitting for tonight but would appreciate ideas on where to go from here. I pulled starter and it tested fine, took brand new battery back and it too was fine......

make sure the ground wire from battery to the body is hooked up, its the smaller of the 2 coming off the negative cable, on the metros it hooks in right behind the radiator overflow bottle

make sure the ground wire from battery to the body is hooked up, its the smaller of the 2 coming off the negative cable, on the metros it hooks in right behind the radiator overflow bottle

Checked the ground as you suggested and it was a bit corroded, so cleaned it up and tried again, no luck. However while I was staring at the ground I noticed a pair of 4 pin connectors on the wiring harness that were not connected; they were about 6" from each other and even with the proverbial "wire stretcher" they weren't going to go together. Interestingly though there was a set right next to them that were stretched tighter than a banjo string..... Unplugged the tight ones and then plugged the respective male ends to female ends in the more relaxed configuration. Tried again and it fired right up! So the "helper" strikes again...... Only took me hours and hours to find it... Now all I have to do is solve the high idle: approx 2500-3000 rpm, the minor surge and the annoying noise coming that appears to be coming from under the timing belt cover . Don't know if this is a side effect of sitting for a year so cruddy gas in the lines is the cause or if there are other issues but at least it runs now, so will continue the quest.

Update: the horrid noise was the bent cam pully rubbing against the back plate (squashed by shipping company, unfotunately I didn't notice it at the install). Surging was a leaking vacum line, high idle was throttle cable too tight so all is well now and I am back on the road with 44mpg city and 53mpg highway.