Electrical issues

I have two problems, one is with the factory car alarm it worked one day and now it does not. Battery in the remote is good and the heater use to blow cold air so I switch the heat hose around on the fire wall then it blew warm now it does nothing. My speedometer quit working. Where is the fuse? It quit after I put a radio in my glove box because the dash plate is round, so more expensive to put in a CD player, but I did not cut any wire's I just unplugged factory radio hardness.