Adapter as in the multislot adapter?
Many of those adapter are really cheapo, and the wiring are badly route, causing shorting to ground. Shorting to ground will blow your fuse, even your cigarret slot 10amp fuse.
I have opened some before to re-route the wire. I notice the + and - are very close on those I have. Abit of twist and turn may cause them to short. If you have a multimeter, your can measure if it's shorted.