I have a JL 1000/1 amp and any time you play it at a med. high volume the amp cuts out and a blue light flashes that reads low voltage. Why and what is causing this? Also what can I do to fix it?

 

you most likely need a new alternator or a cap. also, what awg wire did you use for power and ground?

EDIT: sorry, i didn't read your sig. your cap should be way more than enough to keep a stiff voltage. have you tested the voltage with a voltmeter when it cuts out? it could be the alt or the wiring still. also, what size wire do you have powering the HU. if you're using the stock bose 18awg wire, that is not enough. i had a similar problem with my HU dimming when i first installed it.

 

I have 4 gauge wire for my whole system, and I have it grounded behind the seat where a bolt is on the floor of the trunk. And yes I do have a voltage meter and its droping below 11.5v. I also have dimming but I have had that ever since I got it installed 6 months agao.

 

Have you done the "magic 3" upgrade yet? If not, do it then start thinking about the alternator. Too many factors to work in with changing out the alternator.

 

What is your voltage at the battery? check that first. Chances are that the ground is not real good in the trunk. Check voltage in the trunk from the power wire, and find a bolt or something in the trunk to use as ground as opposed to the ground wire at the amp. If the battery is not able to show at least 14.0 while the car is at about 2000 rpm, then start looking at the alternator. Everybody in this forum is so quick to say upgrade this or upgrade that, when everything I see is usually bad connections, or a problem with the way it was installed. Make sure that everything else is fine before you jump into a $1000 buying spree for stuff you don't need. Doing a multiple battery set up is much cheaper and is going to fix more than the alternator will. If you aren't running 2500 watts RMS or more, you shouldn't have to upgrade anything.

 

Your amp is killer, there is a reason why you paid that much for it. It has a regulated power supply and keeps its out put constant over a wide range of voltage, but yes under 11.5 is too low. But the JL Amps do not need a cap, nor should they put a drain on your electrical system. You might have something going bad, If you bought it at a shop take it back, they should help and it should be on warranty.

 

Some one on www.caraudioforum.com just mentioned that too, I'll give it a try and see what happens.