I've tried to stay away from having to learn car audio my whole life and it seems i've finally got to learn something. I've got a 2000 tt with an alpine head unit and 2 10 in. subs in the trunk. The subs sound GREAT when they're working, but they've only come on like twice in about 100 miles (once they're on, they stay on). It's a new car for me so I have no idea about what amperage or wattage or whatever is going on, bit is seems like maybe a wire is messed up or something. The previous owner said he had a different amp but it was draining the battery so he changed it out.

Like I said it sounds great when they're on but they're spiratic. Ask a question or tell me what to look for, any help would be great!

 

It could be two things...a loose remote turn on wire(the wire that connects to the amp to turn it on and the other side is connected to a 12v turn on wire from the deck) or your amp can't handle both of the subs and are clipping out...find the remote turn on wire to see if its loose and and other wires that might be.

 

I agree. Most amps have an led to let you know when it is turned on. I would check this as well. As far as clipping, I'm not sure if that would be the issue since you didn't say that the amp comes on initially. If it does come on when you first start up the system and then turns off after a little while and then back on again then you could be overheating the amp and it is going into thermal protection mode. Once it cools itself down it will come back on. I had this problem on my S2000 an ended up getting a different amp. Also check and see if your gain is maxed out on the amp. It shouldn't be. The other possibility is that you have a two ohm load on the amp and it shouldn't have less than 4 ohms. All that depends on the actual components and ratings. If you find those out I could help you a little more.

 

im thinking there is a loose wire. Sometimes i'll go over a bump and it'll go out and come back in. I got in my car the other day, used the remote start and they were working, shut the door and they went out. I was bummed so I decided to move around in the car (jump in the seat) and they came back on. I'll be looking for it something this week.

 

Glad to hear you've narrowed down the problem. It is probably going to be one of the three main wires then; power, ground, or remote. Let us know how it turns out and good luck!

 

My bet is on the remote wire being loose becasue mine came loose a couple times

 

will do!

 

Any of the wires may be coming loose (RCA (audio signal), power, ground, turn-on) but the most overlooked connection in amp hookups is the ground. Find where it grounds and if it's not substantial relocate it. If it's in a good spot clean up the mounting location (steel wool or some such thing) and tighten everything up.

 

Yeah if the amp was seeing a 2-ohm load and it was only meant to have 4-ohm (or more), it would either work, or not work. If the protection mechanism was there, it would be permanent. Make sure you also check the fuse for it by the battery on the positive cable. I have seen those fuses blow, and then a piece of melted metal inside making the connection every now and then, but thats a long shot but a quick visual check. My bets are on ground (as previously stated) or turn-on. Also, if you can, do a wire continuity check (buy a $20 multimeter from home depot and check to make sure the resistance of all wires is zero).

I know it sounds like a lot of work, but the way I'd do it is:

Turn on the car, make sure the amp comes on.
If it doesn't come on, pop the hook and visual the fuse.
Assuming that's good, its time to take out the multimeter. Put the Positive on the 5V turn on lead, and the negative on the ground you are using for the Amp (you can use the cable right on the amp), and make sure it reads 5V.
Next put the Positive on the 12V power line on the amp, and the Negative in the same spot (ground on the amp), make sure it reads 12-14V (car off or on).

If you get nothing for both, its your ground (since you were testing the cable right at the amp), if you get only one or the other, its whatever one shows no voltage. If you need any additional help, I'm always glad to try.

 

Thanks for all your post, I have the same problem and now it has been sorted!