make sure that you have a good grounding wire.. this can mae the fuses blow.
Also if you installed it, make sure that none of the wires at the back of the head unit are touching each other with the bare wire ends, just cover the ends of the connected wires with tape, this ensures the wires dont touch each other, also it makes sure the power wire isnt grounding itself if it touches the chassis of the car behind the Head unit.
give it a shot and see how you go.
91' EA II Sapphire
JMM DEV1, MPFI, Lowered King Springs, Monroe Shocks, 16" ROH Rims,CD Player, Kenwood Speakers.