1991 Nissan Sentra No power to lights, horn or anything

Electrical problem
1991 Nissan Sentra 4 cyl Front Wheel Drive Manual? Miles

we did a minor tuneup on the car, just the basics, replaced the battery also. We have no power to anything beyond the fuses/fusable links and relays. I have checked all of the wiring as best I can and found nothing loose or damaged. Checked the current on the backside of the fuse/relay blocks under the hood 12V strongchecked the fuses under the dash all are good. Tried to push start the car as a last resort. Nothing. So somewhere between the fuses/relays something has gone amiss. I was careful during the whole tuneup/battery change to go back the same way it came out.
Any suggestions. TKS Mike