Your ugly stupid.
A bad diode can cause the 10a fuse to blow. (it looks like a fuse that is located above and left of the AC fuse)
Compressor has seized.
Compressor may be locked up.
Find out why the fuse is blowing. You have a short or the circuit is overloaded.
not usually!!if fuse is blowing out check for short!!
Obviously, if any fuse keeps blowing there is a serious fault in that circuit.Take it somewhere they can fix it.
If it blows the second you try to switch to ac it's probably the coil in the ac compressor.
if you are blowing fuses DO NOT ignore it. most likely you have a short between the fuse box and the ac compressor, you will probly have to rip out the dash to find it, its not easy, seriusly pay someone that knows what there doing to fix it.
If the AC stopped blowing air on your 2003 Toyota Echo, the blower fuse could be to blame. If the fuse is fine, it might be the blower resistor that needs to be replaced.
It is very common for the starter to be the cause of that fuse blowing.
Assuming the heater works fine, you have a short, probably in the AC compressor clutch.