I have an 85' S-10 with a 2.8 carb I had it running the alt wire shorted out on somthing now the only power i have is headlights nothing else anyone know whats wrong?

you just answered your own question. fix the short.

the problem is we cant find the short Ive been told that it could of fried the ecm do you know if that is true

is this a throttle body injection system, electric carberator or a carberator? your going to need a very detailed wiring diagram. find the main fuses or fusible links and check them. they were probably burnt from the short.

Look for a fusible link you might have fried. It looks like a heavy wire coming from the power block on the firewall. It will feel thin and soft to squeeze it. couple of bucks from your local auto parts.

Also, check all of your fuses, chances it blew a couple.