[05v6gt]

Okay, I am going to list everything you need first:
1. Sub of choice
2. Aftermarket Headunit
3. Amp
3. Remote wire from Headunit to Amp
4. RCA from Headunit to Amp
5. Power wire w/ fuse from battery to amp
6. Ground from amp to metal frame with unpainted surface
7. Fuses in Amp must be good, same for fuse in power wire
8. Speaker wire from Amp to Sub

First things first, does your Amp turn on?
If yes then you have a problem with the wiring to your sub, or your Remote/RCA's are not working right. The Remote wire should be light blue solid.

If your amp does not turn on, you need to fix your ground/fuses.

There really isn't much else that could be wrong... and your explanation is not good enough for me to be able to tell what the problem is.

95% of Sub problems come from a bad ground. btw.

 

[05v6gt]

I got the stock amp, stock sub, aftermarket headunit (Pioneer DEH-p3600)

sooo those things are for aftermarket sub/amp system correct? im trying to get my stock system to work.

unless the stock sub/amp dont work with aftermarket HU. but i was under the impression that it did.

BTW i never had it working ive owned the car for almost a year and it wasnt working when i got it.

You need to find out if the Amp ever actually turns on, that is your first mission.

 

[05v6gt]

the other speakers are working. does this mean its on or not though?

Most likely not... how many speaker wires are coming from the amp, there will be 2 per speaker. I have never seen the stock amp, I just know how this stuff works.

From what I know the stock amp only controls your stock sub, the amp should have a light that lets you know when its on. Personally I think you should just buy a small aftermarket amp+sub setup.

Since you are planning on using the stock setup, this would be a fairly decent upgrade from it, at a low cost.
http://www.sonicelectronix.com/item_33466_Kenwood-KAC-1502S.html
http://www.sonicelectronix.com/item_33467_Kenwood-KFC-W3013PS.html
This is the amp I use for 2 12" subs( i have 1 bridged for each sub), having the amp all the way up overpowers my stock speakers w/ aftermarket tweeters. I also have a 6.1" LCD Kenwood HU, perfect fit for a tiburon.

This is a mild non-competitive system that sounds good with stock speakers. I ended up replacing the rear speakers with aftermarket 6x9's, and the front tweeters with 1.5" bullets.

 

[05v6gt]

i relly dont want to spend any more money on this. dont care about having amazing bass you can hear from a mile away. just kinda bugs me it doesnt work.

so no the amp doesnt have a light on it. heres a link to the connectors and diagrams.
http://crutchfield.custhelp.com/app/answers/detail/a_id/5620

there are 12 in 18 out. the front speakers get split into the tweeter and woofer.

i need to check the fuse for the amp. just thought of that. probly shoulda done that a long time ago.
the fuse is good. so ill try checking to make sure the amp is getting power. and maybe the amp remote to see if im getting anything there.

If the amp has power, and all other speakers are working then you need to check your subs wires and solder points. If they are fine then something is wrong with your RCA cables or maybe your remote wire.

 

[05v6gt]

Solder points and connectors all look good. I dont have RCA cables. It goes through the stock wiring and the amp makes the sub output.

Try switching around the speaker wires, then if you have a remote you need to be sure its working. I'm running out of ideas here. Try the ground too while you're at it.

Do you hear any "road noise" in the background while you drive? Kind of sounds like you have an electric turbo in your trunk. If you ever experience this, you have a bad ground and its picking up with your engine RPM's, your sub would probably still hit though.