I was driving down the road in a 1969 Chevy fullsize blazer everything just stopped car completely dead won't turn over can not even turn the headlights on does anybody have any suggestions check the battery alternator starter they all seemed fine.

 

Check all your grounds. clean the connections at the battery ect.

 

Is it a top post or side post?
My 96 Silverado had a similar occurance. The tabs on the cables had dug into the battery to the point the cable would spin and the bolt would not hold them tight.
A washer between the cable and bolt fixed it.

Other then that I would start with checking all your connections, bat, starter, alt, and agree with grounds.

 

I'd also suggest if it's a 69 to look at the voltage regulator...