A short circuit somewhere.
i replaced the head unit and the fuse stoped blowing.
not usually!!if fuse is blowing out check for short!!
Find out why the fuse is blowing. You have a short or the circuit is overloaded.
Obviously, if any fuse keeps blowing there is a serious fault in that circuit.Take it somewhere they can fix it.
It is very common for the starter to be the cause of that fuse blowing.
Wrong amp of fuse
A short.
There is a short. Shorts blow fuses. The motor may be bad - or need lubrication or a short on the wring leaving the fuse box to where ever it goes. Unplug the more and try a new fuse!
for fuse to keep blowing, there is a short in the eletrical system somewhere. check the a/c switch and the a/c clutch
Fuel pump
A over current condition in that circuit.