i just got this blazer, speakers on teh dash work but the 2 on the doors dont work nor does the 2 on teh back doors dont work. i changed the head unit still dot work. jw if anyone had any good thoughts.

 

could be blown? wiring may have get weird. One of my speakers didn't work when I got my blazer. I put all new speakers in seemed to fix the problem

 

one of the speakers that doesnt work probably has a grounded wire, you can find out which one by probing your decks wiring harness with a multimeter on resistance. sometimes having the wires grounded, or touching each other will make all the speakers cut out that are on the same amp.

 

or if they are the stock speakers, try rewiring them without the plugs. It worked on mine.

 

It drove me crazy why my back speakers did not work till I took them out and hooked up new ones works fine so take the dooor panel off hook up and you will find out they were toast