1990 Chevy Suburban half of everything works

There should be 2 maybe 3 red fusable links coming off the terminal on the starter where the main battery cable attaches. Check these for voltage. Sounds like you may have blown one of them.

ok i think i located all of them but is there an easy way to test em without piercing the insulation on the wire i live in michigan salt loves copper it looks like they are plastic couplers joining wire to the link but dont see how they come apart

The fuseablr links won't come apart. The best way I've found to test them is with an ordinary "stick pin". They leave a very small hole and can easiy be civered with tape. Just be careful you don't short it to ground.

there must be some sort of relay the fusible links all test good at least he ones i can find everything that is out on the fuse block is ignition on items where is this relay at and how do i switch it out?

OK, Ihave looked at the diagrams for your "power distribution", what few I have, and everything you are missing power to comes from a single fusible link from the starter. At this point, we need to look at the back if the fuse block and check for any "opens" in the links of the block. Check this out and let me know.