Accesory Power Fuses on 2002 Chevrolet Avalanche 1500

I am having problems with my fuses blowing on my trucks accessories below my radio. I have a 2Amp Radar Detector & a 3Amp GPS that burn up almost instantly. I also have an adapter that creates power for a power receptacle that does not blow it's fuse. I have checked all the other fuses in the vehicle. What would cause this to happen?

What is the fuse rating for the accessories fuse? Try disconnecting all the accessories, replace the fuse and plug in each accessory and find out which one is causing the fuse to blow.
Problem is resolved. It was a short in the line of my GPS that was causing the fuse in the GPS adapter to blow. I done an Ampacity test with an Handheld electrical meter & found the problem.