Hyundai Repair: Short fuse., amp fuses, 2002 hyundai sonata

Question
I own a 2002 Hyundai Sonata.  Recently ive had a problem with the fuses.
After installing a headunit in my vehicle a couple fuses had blown.  It caused
my tail running lights not to work when I turned on my lights at night (when i
hit the brakes however those lights still worked).  It also caused my cluster
lights not to illuminate. I replaced the blown fuses with the same amp fuses
and they popped as soon as I placed them in.  I then replaced them with
slightly more higher amp fuses and the problem seemed solved. About two
weeks later the problems were back, however, none of the fuses seemed to
have blown.  My rear running lights and cluster dont illuminate at all. The
brake lights work when I hit the brake pedal but dont run on their own.  What
is the problem and what can I do to solve this? how can i prevent it from
happening again?

Thanks for your help.

-nick

Answer
Hello Nick,
It seems that all your problems started after headunit installation. So, first step should be to undo this. Try to disconnect everything on that head unit and see if the problems solved. Do not use higher fuses because it might cause more problems on the harness. If you still have the same problems , all related systems must be checked. Electrical problems are hard to find and can be tricky. If you have experience on this field, try to measure the load on the fuses. If they have high load than you need to disconnect related system connectors (like cluster, tail light etc.) one by one to see if load turns to normal.