Radio voltage Problem

I installed a new radio in my jeep and I keep blowing the fuse on it. I blow it whnever I turn on the jeep. It runs fine when it is not on but it pops when I turn the jeep in. I have it wired to a extra power box that is "hot" when the key is not turned. I was just wondering why it is doing that and what I can do to fix it. Is there a voltage regulator or do I have it wired wrong? Any help is nice.

 

sounds like it is wired wrong, can you get a pic of it?

 

That is a strange problem. Make sure that the ground for the radio is good - add a separate ground wire from the case to a good ground like the instrument cluster ground. Generally voltage surges won't blow fuses but current surges will. Does the radio work when the Jeep is running, ie if you turn it on when the Jeep is running? The starter motor could be making an inductive kick-back that's in the radio circuit at start-up.

Also, the radio may draw more current at higher voltage, ie when the alternator is making 16V or so. This could pop the fuse if the fuse rating were already marginal for the radio. What size fuse are you using, and what does it call for in the radio instructions?

 

The fuse that I am using is a 250 V. It is the same kind that was in there when I bought the radio. The radio does trun on when it is off before the jeep gets started. I seems like maybe the ground isn't very good but is that something that can break a fuse?