check the grounds in your ignition, all the way to the coil. if it isn't grounded right it will switch to "switched power" like in the first position in the key.
most stereos will not run if they dont have 10 volts because they put a safety in to not short the battery if you left your keys in for a long time w/o the motor running
most stereos will not run if they dont have 10 volts because they put a safety in to not short the battery if you left your keys in for a long time w/o the motor running