Audio Systems: Kicker 1200 going in and out of protection, rca inputs, heat detector

Question
My friend gave me a Kicker 1200.1 and when I hook it up it stays on for a second and goes into protection and back to on, the amp does this for as long as you keep it connected. I disconnected the speaker wires but it did the same thing. My question would be how would I find out what the problem is inside the amp

Any info would be greatly apperciated

Answer
Tough one,  did your friend have any problems with it?
There are several things that can make an amp go into protection, over power, possibly under power from your car (use a meter to verify that you are feeding it between 9 and 14.4 volts) short in the speakers, and some amps detect if there are no speakers so make sure you have something hooked up to it but be careful, if there is a problem inside the amp it could blow the speaker. There is also a heat detector that will shut the amp off if it's too hot, this may have gone bad and it thinks it's overheating.  
Hard to say really.  Check your power, make sure your ground is good (not on a painted piece of metal)remove the RCA inputs so there's no hum or any noise or sound entering the inputs and give it a speaker you don’t care about on the speaker output and see if it stops doing that.
As far as tearing the amp apart and trying to find where the problem is, you will need to know a fair amount about electronics to have any chance of fixing it.  The most likely things to go bad inside are the transistors,  they are the little black squares along the sides of the amp.  they have 3 wires on each one and there is a meter that can test them without removing them from the circuit.  that's about the best bet 2nd to just buying a new one if the other tips don’t work.
Good luck.