Alpine MRP-M650 problem

Check your speakers and speaker wires to make sure you have no shorts or grounds. Not knowing what vehicle you are putting the amp in, there is also a possibility that there may be a stock amp in the vehicle. If this is the case, you may have to rewire the speakers and bypass the stock amp.

sub spec 250watts per coil you should be just fine I have 2 typr 15s on orion hcca 2500 1 and it kicks a$$ thats 1000 watts over the rated limits of the subs only shut the amp down once these subs can take a lot more power than they say just use your common sence with the volume and gain levels

sounds like a short. did you check the amp fuse and the fuse on the power wire (under the hood) make sure there are no wires touching. most common is the wires to the sub touching on the amp. let me knwo if that helped

no it could one 12 but no 2 and def not a 15 when mach speakers to a amp you want to mach up the rms power you want to amp to put out enough to power bolth speakers so like 2 500 watt rms you would want a 1000 watt rms amp

bad amp or bad speaker wire ground

It sounds like it may be going into a protect mode. You may be overloading the amp. You might want to go higher impedance and take it easy on the amp. The internal power supply MAY be collapsing under the load.

Don't believe all the numbers that manufacturers put out... we call that "Specsmanship"... in other words INFLATED numbers so you buy ours instead of theirs.

if you changed the both fuses you mean the amp fuse and the battery?
remember there is a fuse right next to the battery and i believe 2 at the amp.

USE A HI TO LOW CONVERTER A GOOD ONE BUT ALSO MAKE SURE WHAT KIND OF FACTORY SYSTEM IS THIS BEING HOOKED UP TO BECAUSE IF THERE IS A FACTORY AMP GET THE SIGNAL BEFORE THE OUTPUT

Some AMPs have a thermal cutout, that switches the amp off if it gets too HOT.

But this sounds like your amp or sub is screwed, either there is to much resistance in your sub, eg: Burnt voice coil, carbon builds up on the coil stopping the sub from moving freely. Push on the cone of the sub & listen for a scrapeing sound.
or test this by continuity testing the sub terminals & pushing the cone if the BUZZER on the MultiMeter cuts in & out as you push & release then your sub is screwed. ( a certain amount of repeatative pushing it may free up the voice coil.)

or your Amp may have blown a internal fault that will have to be sent of for repair.

Or you have a incorrectly rated fuse for your system,

or the battery cant kope with the power surges???
THIS DOES NOT APPLY TO YOU AS YOU HAVE A POWER-CAP!!!

is the remote lead properly connected to the head unit? if the power led is on then the power cable and earth must be good, check the remote lead 2 your head unit first, if thats all good try looking at the amp to see whether theres a small switch to adjust the output going to the subs, if its very low or right off then nothing will be going through to the subs. if its on high and fine it only realy leaves the neg and pos inputs from the amp 2 the subs.

cheers, adam