one day blazer was hard to start {took several cranks } before it started. next day would not start @ all . acted as if it wasn't getting fuel , few days later tried again and it acted as if the battery was low {crank then dash lights go out only clicks} went to charge battery only to find battery was full.I turned key to acc.dash lights turned on then they shut off, turned on again then shut off.vehicle will now not do anything, try to start and nothing no dash lights no click nothing.. please help Dave

 

Welcome from Florida. Check your battery cable connections at both ends also for looseness and corrosion. Also make sure the alternator is charging properly.

 

will do thanks for in help

 

That's a wide range of possible issues, I'll list all I've encountered.
Ignition switch control module under distributer cap faulty, injector o-rings worn, bad battery connections (did a big three upgrade to fix), bad fuel filter (or fuel pump), low battery (if it's dead long enough, it'll never take a full charge), bad ignition coil (or bad ground connection to, some models develope a loose connection) and bad ignition switch (located in cab above steering column).
Best bet, is start with cheapest issue, and work your way up.

How this helps.

 

Did you ever solve the issue?