alternator making bad noise went to pull up on ramps with door open to see . went dead and wont crank .will turn over but wont crank . replaced alternator with used one . replaced coil pack . replaced crank sensor . still wont crank. did key dance and got codes 1684 and 1388 also check engine light blinked 10 times after codes said done . can anyone tell me what problem is and what to do please !!!!!!!!!!!!!!!!!!!!!!!

 

Turning over and cranking are the same thing. So it turns over but won't start?

 

Crank is the same as saying turn over. Your title should read 'wont fire/start up'.
The code is pointing to the ASD relay circuit, so that's something that you should test.

 

how ?

 

Google.