Just bought a 1990 4x4 blazer yersterday and the radio does not work. It is a Kenwood KDC-135 and removed it to see if anything was wrong but did not find anything. It has the antenna and wiring harness yet does not turn on when I start it. Any answers would be very helpful.

 

most aftermarket headunits have a fuse to the power. check to see if the fuse is blown. there may be fuses in the back check those too. It could have also blown the fuse in your truck. check the radio fuse that is in your truck. if none of that works your head unit might be broken