Alright here is the deal:
For some reason my friends stereo is cutting out when he turns it up. The Kicker amp goes into Protection at the exact same level every time. To the point where he can pinpoint it on the beat!
Here is the list of stuff:
2001 PT Cruiser
Pioneer Avic-N1
Sony Xplod 4 channel, forget the model
Kicker 400.1
2x Kicker Comp15, sealed box

I have tested with a voltage meter and before the cut, it stays around 13.6 volts. After the cut, the voltage at the amp measures ~6-7, but 13.6 at the batt. I have checked the ground, the batt connection, signal inputs, and the speakers dont SEEM to be shorted.
The wierd thing is, if you turn it back down, it stays in protection. If you take a light bulb and touch it to the termanals on either amp, the bulb lights up and the amp reverts back to normal operation!!!
Any clues???

 

how are the kickers wired up? might be too low of a impedance for the amp to handle.

 

Could be a number of things. How are the two amps wired up? What gauge wire is used and what kind of distribution is used?

 

forgot to say its been running perfect for the past 5 months...

the comps are 4ohm svc, wired parallel - 2 ohm

its 4 guage going into a 2 way distribution block for both positive and ground.
for signal, the sony is getting 4 channel from the avic-n1 and the kicker is getting the sub signal from the sub out.

 

anything???

 

Only thing I can think of is the amp is messed up some how.

 

make sure the subs are actually putting out the ohms you wired them to. Disconnect the speaker wire going to the amp and take a multimeter to the back of the box each set of terminals and make sure each sub shows 4 ohms or 2 ohms if you have them wired together inside the box. Also try disconnecting the speaker wire from the amp and then turn it on and see if it goes into protection

 

that kicker 400.1 is 2 ohm stable. but check the load like DcMaN suggested to make sure it really is 2 ohms final load.

 

2 possible issues as mentioned above....amp is not seeing a safe impedance(check wiring and all voicecoils w/meter) or the amp is faulty