[soundman98]

i always reinspect the part that changed. first step is to return to the stock radio, and make sure nothing changed, then inspect the adapter harness for likely miswiring. optionally, try a different aftermarket radio to confirm a miswiring(same final problem, different known-good radio, just in case the one you've got is a dud)-- but that should be a last resort, as most people don't have extra aftermarket radios laying around, and they rarely do anything that would cause fuses to blow.