ok so yesturday i just got one of my old 12' back and my alpine amp.so this morning i hooked everything up but when i turn the cd player on the amplight lights up and blinks and the sub does not work.the sub is good, im wondering is it my amp or maybe something else?the amp is an alpine mp450. tks

 

Did you check to see the wires inside the box for the sub to make sure the connection was still good?

 

yup, tested and they were working bofore i put them in my car.is there anyway to test the amp to see if it is still good?

 

If you have a smaller wattage sub you can try that to test if the amp is trying too hard on your 12... or this may be a dumb question, but if you don't drive your car - haven't started it lately, a low battery will do that to your amp.

 

I've never heard of that happening chunkbird.

What color is the blinking light, green or red?
If it's red, your amp is in protection, and the problem could be several things.
If it's green, you may not have connected your RCAs properly. If you put your ear close to your sub and you hear a very small buzz or hum at least you know it is not a connection issue, but you risk the amp turning on and permanently losing your hearing :P
so therefore, is it green or red?

 

its actually a blue light on top of the amp.usually when the cd player turns on the light stays blue, but now it blinks and no subs

 

It's probably in protection mode which means something is wrong
there are farrr too many possibilities though
worst being a blown amp
check your amp fuses
check your grounds
make sure it's wired to the right ohms

 

It happened in my car two weeks ago when I was listening to the radio and building my box. When I hooked everything up, the amp light went red and I thought I had ruined it - then I went to start my car and the battery was too low to start the car or run my amp. So yes it is more likely protection mode, but to letWiplash know all the possibilities since he said he had checked all the wires... I gave him another option.

 

Did you replace the battery ? how did it turn out?

wiplash is that the only light on your amp?
If so i can almost 100% guarantee it is in protection mode
I would seriosuly consider checking your grounds and wiring again

 

Na dude, I had to jump it was all. Soon as the car started I flipped the amp switch and bada-bing music! I had to put an on off switch for when my wife is in the car - she no lika da bass