Wiring amp/sub to stock 03mp5 deck?
 

Would anyone recommend doing this? I found a good deal on a 10" sub and amp, but I don't want to ruin the look of the stock interior dash. Do you guys recommend trying this or is it not possible/not worth it?

Thanks

I did it and it sounded great! I put an Infinity Basslink in my hatch area.

I added a self-amplified audiobahn subwoofer to my P5, and kept the stock deck because it has the in-dash 6 CD changer. There are a few wiring issues you'll need to keep in mind in order to do this correctly:
1) Use an appropriate speaker line to RCA output converter. There are no RCA outputs on the stock deck. This will set you back about $20-25. I tapped into the right rear speaker from the B-pillar, and hid the line level converter within the b-pillar (after adjusting output level).
2) To tap into the ignition feed, I found it easiest to splice into the yellow wire behind the stock deck. The rest of the harness is intact.
3) The main power cable can be routed through the main wiring harness grommet in the passenger footwell. I have not experienced any electrical noise from doing this.
4) The rear seat bolts make good grounding points.
5) Use a soldering iron and shrink wrap when you do all of the wiring. And, keep the RCA lines distanced from the power cable and other wiring, to avoid noise from inductance.
If you need any advice or pics, please let me know.

I can't remimber exactly why but when I had my new system put in they took out the one I put in and saw that I used the set bolts for a ground and said that was a big NO NO! They gave me a reason but it was like I was 5 again, all I could do it look at the new stuff in the car and tuned them out. I would call an install place to find out why. O just do like the did get a little sand paper clean a spot and drill it in to place.

If you are wondering if a ground is good or not, take out the ol' multimeter and measure the resistance between two exposed metal parts on the body. And, check for potential pinch points around the wire. If there is no chance of the wire being damaged and the connection is good, it's a good ground. I stand by my recommended location.

Theirs nothing wrong with using the seatbolts as long as you have a clean surface and are getting no resistance out of it.

juddz: some pics would be great, I've only wired a stereo once in my life and it took a while and was pretty messy. I'll PM you or if you want, post them here! Thanks

EDIT: nm you can't be PMed. Maybe post them online?

Perhaps they meant 'don't put the grounding connector between the seat frame and the chassis' - safety engineers would have a cow messing with the integrity of a critical safety item like the seat structure...

I just drilled/sanded a new one next to the amp.

What do you need photos of specifically?

Actually it had something to do with having the ground on a part that is on top of another part (if that make sense)! You have the seat bolt that touches the seat bracket that touches the car, that part of the car is painted so the ground is actually coming from the treads of the bolt not the seat bracket! I had mine there and they had to replace it so that it was directly grounded to the car not the seat. I’m not saying you cant, I did and didn’t have any problems until I added another amp. That’s when they replaced it.
As far as checking if you have a good ground or not, not every one (including myself) knows how to use one of those thingys! I tell if it’s good or not the old fashion way, if it turns on plays load and clear then your good! :bigthumb:

juddz: if you have pics of the wiring configuration to the stock deck that would be great [using existing wiring plus new amp/sub wiring]

You'll only be splicing one wire into the harness near stock deck - the switch wire which turns the amp on. This wire (purple, in my case) will be spliced into the yellow wire behind the stock deck. Leave the rest of the harness alone.

You can take your signal (input) off of a rear speaker. But, Mazda has these funky connectors to get the harness through the door jamb, so you are better off taking the speaker out, identifying those wires which go to the speakers, and locating the same color of wires inside of the B-pillar harness and splicing into them there for your RCA converter. There is very little slack in the harness, so you'll have to be careful when you splice in. Unfortunately, I would have to tear the car down (again) to show you this pic. But I will do it if you really need this photo. The switch wire splice noted above is pretty self explanatory.

I started wiring amps and stuff in high school, over a decade ago now. If you haven't done it before, don't worry - it's nothing you can't handle. Most amps come with a good set of directions, and we are there for you as well. Just make sure you have a soldering iron handy when you do it, use electrical shrink wrap to insulate all your connections, don't forget to put the fuse block close to the battery on the positive power lead, and make sure you buy a good set of wires in the correct guages for everything. Radioshack used to sell a nice wiring kit for amps with top-grade copper wires in heavy (low resistance) gauges.

Give me a few days to get the pics. When are you planning on doing it?

Oh no way juddz! Thanks but no need to tear apart your car! I just assumed you already had pics done up from before. That's a good explanation though, I will give it a shot, hopefully without damaging anything. I am still have second thoughts though--possibly going to professional installation but I'm not sure if they'd know how to handle those tricks (RCA/splicing..)

They do it all the time!

OK my mistake then! Thanks for all the advice!