Here's a basic rundown on how to gut the BOSE gear from the
car and replace it with something worth-while. I wrote it for my specs
but the idea is the same for other brands.
I made up 6 phases for installation:
1. Rear Speakers
2. Front Speakers
3. Head Unit
4. Main Amp and CD Changer
5. Bass Amp
6. Stealth Box
Unfortunately, my car is in the shop I can't take any pictures. I might
make a mistake somewhere since I'm writing this from my memory.
Tools you might need:
- 10mm socket and driver
- Phillips and flat screw drivers
- Clip popper
- Wire stripper
- Box cutter
- Electrical tapes
- Soldering iron
- 6 door clips from Nissan, 'cause you're gonna break them!
- Multimeter/volt meter
- Electric drill
- Lots of ice for headaches :-)
Disconnect the negative terminal of the battery.
1. Rear Speakers:
Remove rear interior panels first. Remove the rear carpet. Go from the
center plastic panel, unscrew the two plastic screws by hand, unscrew the
2 10mm nuts (all nuts & bolts are 10mm) at the lower corners of the
center panel. Remove this panel. Then go either left or right. Same thing.
Go left in this case, unscrew 2 nuts. Take a flat driver, pop the plastic
taillight cover off. Unscrew the nut under it. Remove the corner panel.
Three nuts for the rear speaker case/cover. Pop out the plastic cover which
behind the driver seat (ahhh, headlight aiming tools!), remove 2 nuts.
Remove rear speaker cover. Now rear Bose enclosure is uncovered. Disconnect
speaker connector(you might have to remove the speaker to do that, cant
remember). Remove Bose enclosure (3 x phillips). Replace with a 4x6" driver
in non-Bose bracket. Do the same for right side. Run equal legnths of speaker
wire from the rear drivers to the package tray where the main amp will
go. Dont put back any panels until everything works.
2. Front Speakers:
Driver and passenger sides are slightly different. Go from driver side
first. Open the door and roll down window. Look into door handle grip.
Take the little cover piece out. 2 10 screws, remove them. Pop the window
and lock control panel piece out. Disconnect electric connector.(Passenger
side: pop out the insert cover on door handle. Remove the screw inside.)
At the top of seat belt, there's a half round cover on the vinyl cover.
Pop it out with a flat driver. Under that there's huge bolt. Unbolt it
(Half the belt will be hanging.) Carefully open lower half of the vinyl
cover(doesnt come off all the way). Under that 2 10mm bolts hold a door
cover bracket. Unscrew the 2 bolts. At the bottom of seat belt there's
a seat belt cover, remove the two screws. Take the cover out. Use clip
popper to pop out door clips at the very bottom of the door (3~4). Open
the door all the way, by the air vent there're 2 more screws. Remove them.
Hold the door panel upward, it'll now come off. Seat belt will still hold
it in place.
Disconnect speaker connector. Remove Bose enclosure (3 screws). Measure
off two equal lengths of speaker wire that will run from the drivers in
the door, under the dash, down the center console to the package tray where
the main amp will go. Run each of the speaker wires from the door through
the wireway/grommet into the cabin, under the dash, into the center console
behind where the head unit goes, then run each wire down the center console
(look here to see console
removal tips) to the package tray. Install the non-BOSE bracket. Connect
the speaker wires to the new 6.5" drivers. Install the drivers into the
brackets. Dont put back door panel yet. Testing first!
3. Head Unit:
Remove center console trim ring around the radio. Pop out two little
plastic covers at each end of the top air vent. Unscrew the two screws
under them. Pop out the plastic trim piece right above stock BOSE radio
using a flat driver. Remove those two screws. Take the center console trim
ring out (2 clips at bottom, just tug it free). Disconnect the closer wiring
connector. Remove 4~6 screws, the radio with its bracket will come out.
Disconnect harness plug, ground wire and antenna. Remove the 2 screws on
each sides to remove Bose unit. Screw aftermarket head unit on the bracket.
Plug the Crutchfield adapter plug into head unit and BOSE harness plug.
Screw the ground wire in. Plug in the antenna. Plug in the RCA cables to
the pre-amp output for the main amp. Plug the CD control interface cable
(black), plug in CD source audio cable (twin, red and white). Put radio
bracket back in place but don't screw it in yet.
4. Main Amp and CD Changer Install
There're probably other places to mount them but I mounted them on the
rear deck for good heat conduction and clearance. Remove the rear package
tray. There're 8 10mm nuts mounting the package tray to the car. 2 on each
side. 4 more on the side facing trunck. Take the package tray out. Mark
the holes where screws will be in place to mount the amp the CD changer.
Make sure there's enough clearance for RCA cables, power cables, ... also
enough room to pop out CD magazine. the '90-'91 deck is slightly smaller
than '92 and up. Cut a 1" or so diameter hole for all the cables. Secure
the amp and changer with appropriate nuts and bolts. Changers can be mounted
vertically or horizontally. I mounted mine horizontally for space. A cover
can be easily made for anti-theft reasons.
Remove passenger seat (4 x 14mm). And disconnect the passenger seat
sensor (for seat belt warning light). Take the seat out. Hold the bottom
edge of passenger side interior trim starting from shifter boot, pull the
carpet out all the way back to end of the trim.
Pop out the screw cap and remove screws on each side.
Remove two screws on top of the center cover. Remove the cover.
Drill a .5" diameter hole on the firewall next to driver side fender.
There're other ways to wire battery cables, but I think this is the easiest.
Connect 2 power cables to positive. The amp cable should be at least 10
gauge, more powerful amplifiers require thicker wire, consult the amp's
instruction manual for details (the smaller the number, the larger the
wire). Make sure to put a fuse in-line as close to the battery as possible.
Tape both cables to a 3' long thin metal stick. Push the stick through.
Should be able to see it inside the car right by the clutch & brake
peddles. Pull the cables out and remove the metal stick. Use touch up paint
to cover up exposed metal and seal the hole with a grommet.
Pull all the cables (4 RCA cables, CD control interface cable, CD source
audio cables, f/r channel speaker wires, speaker level output wires from
head unit. 2 battery cables, remote cable) through from the carpet opening
to the rear deck. Connect all cables to main amp, CD changer. Make a secure
ground to car chassis for the amp. Important to sand off paint and rust
for ground. It's always a good idea to ground the amp cover. It reduces
5. Bass Amp:
Most bass amps are smaller mono or 2 channel amps. I would mount it
under passenger seat. Cut a 1" hole in the carpet for power cable, ground
cable, speaker level input wires, remote wire, speaker ouput wires. Mount
amp with 4 screws or simple stick to carpet will be enough. Connect all
cables. Connect speaker level input to the bass amp. In my case, I have
50x2, 125x1 amp. So I would bridge the output. Pairing the left positive
and right negative (see amp diagram for details).
There're three screws the bottom of stealthbox. When the stealthbox
shipped, it came with a precut cardboard which are used to drill holes.
In my case, I lost it. Easy solution. Screw three bolts onto the stealthbox.
Put white teflon paste or coloured silicon on back of the bolts. Put the
driver side rear panels back on. Remove trunk carpet. Carefully place stealthbox
at the left corner of trunk. Make sure the three bolts leave clear marks.
Drill the holes. Connect the speaker wire. Go under the car, and mount
the bolts through. I would not cut the trunk carpet, I'll just fold it.
7. Make it all work!
With Crutchfield adapter, you don't have to cut any wire. But since
there's a main amp here, we have to cut the front speak wires. I think
they're both white. Cut them AFTER crutchfield adapter. Connect speaker
output from amp. For rear speakers, run wires directly from amp. Make sure
remote on/off wire is
connected to both amps. Power and ground cables are good.
When I first installed them with my friend. It took us 12 hours! To
do it yourself, you should reserve good 2~3 days.