Alpine M350 Cutting Out, Not Off

Well, here's my 1st post. Been reading and learning a ton, but now need guidance.

I have a 98 F150. Am have a Pioneer HU (3 months old) witch is running all of the factory component speaks. I also have an Alpine MRP-350 which is pushing 2 Kenwood subs in a sealed box. The subs are 2 ohm stable and are wired in parallel which gives each sub 175 W RMS (which is the maximum per sub rating) and puts a 2 ohm load on the amp. (reads, I think this is the set up I have)

I installed the HU, Amp, and Subs at the same time and everything ran perfectly for about 3 weeks. Just recently, I've noticed that while driving and listening, the subs will stop producing sound. It doesn't seem to be related to HU volume as I've been listening to the radio at a low level and have them stop producing. When this happens, the Blue light which represents power to the amp is on and it as bright as always. The subs just aren't moving. 

Sometimes, if I turn the HU off and wait for the blue light on the amp to go off, then turn the HU back on, everything works fine. Sometimes, I have to turn the truck completely off and then back on before it will work again. Sometimes I try both and nothing will work. Then, next morning, boom-no problems. Sometimes I can drive for an hour with no problems. Sometimes it happens in the first 15 minutes. Again, it does not seem to be volume adjustment related, nor truck moving related.

Is the amp going into protection mode? Any thoughts?

Eightman

No, they are 4 ohm. 10" Kenwood 4 ohm subs. Rated at 175W RMS peak.

I will say that the system worked perfectly for approximately 3 weeks (at any volume and for any lenght of time)...

I've made no changes to anything and cannot seem to find a pattern as to what sends it into protect mode???

-eightman

When any system is working fine then stops working, one of two things has happened.  Either something has changed or been changed, or something has broken.  If you have not changed anything and if you have no loose connections or corrosion on your battery terminals, etc. then either your amp or your speakers has been fried, or your alternator is being overloaded and is starting to die.  What is the voltage at the amp? How is your gain set?

I will have to check the voltage at the amp. The battery and alternator are new within past year (prior to amp/sub install). I have no light dimming issues/other wierd electrical issues. Should I assume that the amp is going into protect mode? The amp itself only has a power indicator. As I mentioned, when, in what I assume is protect mode, the light is bright. It will normally being to function properly after I power the HU and amp down and then back up. Sometimes, it will take a while though (like it's not being reset immediately). Could I have a short in the RCA's from the HU out's to the amp? Could it be a short in the speaker wire going to the subs?

Where would you guys recommend I start the process of elimination?

-Eightman

Oh and the gain is set at about 1/2. Also, could this small of an amp overload my alternator?

-eightman

i just did the same thing and i found out my subs are blown out. ill hope for you but thats possably what it is, if thats the case thats probably why its going into protection because its shorted, but check your fuses see if theyre popped

I would be surprised if the subs are blown. When the system is working, both subs still sound very good and hit hard. No distortion, cracking, popping, etc.

-eightman

If the amp is staying powered on, it could be that you have some exposed wire strands that are intermittently touching metal or shorting to each other.  Pull the subs and double check the wiring.

As far as the alternator, I doubt that's the problem.

Thanks for the advice. As for now, that seems to be the best (reads... easiest)place to start.

-eightman