Replaced head unit 03 SR5
I did a similar thing...
I had my original stock JBL head unit replaced with a JVC KW-V200BT at a local sound store. They did a great job and hooked the new JVC head unit to the existing stock speaker wiring and steering wheel controls. It works great and I love the Bluetooth access to my Droid phone and stored music.
Then downside of this was that my stock speakers were old, crusty and the driver's-side-rear-door speaker was broken.
So, this past weekend, I replaced the main speakers in all four doors (using instructions from other posts on this forum) while keeping and using the stock speaker wiring to and inside each door and the stock black plastic speaker housings. It made a HUGE difference and upgrade in sound! For the front doors, I installed new JBL GX-963 6x9" 3-way speakers. For the rear doors, I installed new Alpine SPS-610 (not 610-C) 6.5" 2-way coaxial speakers.
To do this, I:
- loosened and pulled away the door panel in each door,
- then I unplugged the white plastic plug which connects the wires coming from the head unit to the black plastic speaker frame housing mounted to the door,
- then removed the stock black plastic speaker frame housings from the doors (4 screws each).
- Then I took all four old speaker frame housing units containing the old speakers inside to my kitchen table "workshop".
Once inside:
- I unscrewed and removed the old original stock JBL speakers,
- pulled them off the black plastic housing frames,
- and screwed in the new speakers into the original frames (with a little thin foam spacer between the new speaker and the black plastic frame).
- I also reused the stock red/black wiring tail which is INSIDE each black plastic frame that connects the individual speaker spade connections to the white modular plug connection fixed into the black plastic frame housings. I took care to match the positive and negative polarity of each speaker to the proper polarity of the original door speaker wiring.
By reusing the plastic frame housing and its internal red/black wiring tail, that allowed me to do the old speaker removal, new speaker replacement and wiring in the comfort of my kitchen table.
- Then I took the newly refurbished frame/speaker units back out to my 4Runner, screwed them back onto each door and plugged the original door speaker wiring plug into the white plastic receptacle of the black plastic speaker housing.
Door speaker replacements are complete and I love the results!
NOW, finally to your point about the sub-woofer, I am thinking about how to replace the original stock subwoofer in the back, since it just thumps a little and doesn't provide much sound. My objective for that project will be to improve the bass sound while keeping the original stock look and configuration. I'm not interested in creating a subwoofer system powerful enough to send extra-low-frequency codes to subs in the North Atlantic. I just want a simple upgrade using as much of the original stock wiring, power cabling, and fusing as possible. I'll post my progress here when I get it figured out.