Car Stereo Replacement HOWTO

By David W. Jeske (copyright 1998)

Posted by David W. Jeske on February 02, 1998 at 11:58:32:

In Reply to: Stock Stereo Replacement posted by Farid on February 01, 1998 at 07:45:30:


Hello,

: I sure that this topic exists about a mile down the list.
: I am interested in replacing the stock stereo and comps. 
: in my 98 Leg Out. Thinking of adding new reciever, 
: speakers w/comp tweeters and CD changer. How difficult
: is it to take out the dash for receiver replacement.?
: Anyone recommend a decent mail order car stereo catalog.
: I have Crutchfield but their prices seem to be same as
: local stereo store. BTW does stock radio have any amp.
: outputs? Any help appreciated.


Specific questions first. Crutchfield has great wiring
harnesses and overpriced stereos. Look in the back of
_Stereo Review_ magazine for cheap places to buy stereos.
Normally stock radios have amplified outputs. Some cars
(particularly recent model fords) have separate amplifiers
located under the front passenger seat, so the stock stereo
has pre-amp outputs. 

If you have any more specific questions about your car,
post them here or email me at: (my first name and first initial of last name at gmail.com)

*** CAR Stereo Installation HOWTO: ***

Let me preface this by saying I have not replaced the stock
stereo in my subaru (yet). However, I have replaced stock
stereos in four cars, and know people who have worked at
car stereo replacement/upgrade places in the past. Also,
don't let the length of this scare you, I'm just trying
to be thorough and give you an idea of what you are getting
into. If you use a screwdriver you can replace your receiver.
If you can splice a wire, operate a drill, work a ratchet
wrench, and read a car manual schematic, you can install
just about anything in your car cleanly.

First let me say that it's not very difficult, _IF_ you are
careful, you get the information required first, and you
don't try to take anything apart that you don't understand
how to take apart. However, depending on how extensive of
a job you are doing, you may have to handle seeing your
car interior in pieces. (In my last car, an 88 Accord 
htchbk, I had all the seats lying out on the driveway, 
and half the carpet lifted to do wiring for my "remote
mount" HAM radio stuff and CD changer.)

The stereo replacement places I have any information about
(through friends) would not do nearly as clean a job as
I did. Generally they operate with the following ideas:
1) get the stereo in so nothing is exposed to the interior
2) get it in as quick as possible

They certainly would not have had the seats out of my Accord
to do my installation, they would have jammed all four
sets of wires down the side channel. 

If there is one thing that is the most important, it's
to TEST IT before you assemble everything. There is nothing
more annoying than spending three hours installing stuff
just to have to take the car apart again because one of
the wires is crossed or something.

A word about Crutchfield. They certainly are just as
overpriced as your corner store. I buy things from them,
and certainly use their catalog "fit guides" for receivers
and speakers. If you are price concious you can buy the
same stereo crutchfield sells for 10-40% less by buying
it from some small place found in the back of a _Stereo
Review_ magazine. However, if you are of high morality
you'll buy your stereo from Crutchfield because their
catalogs and wiring harness are going to save you
countless hours of trouble. (back in my school days
I would just buy the wiring harness from Crutchfield and
the stereo from el-chepo COD only store)

So, I'll start from the beginning:

1) Replacing a receiver:

The easiest thing to do is replace the stock receiver.
The best way to do this is to call up Crutchfield
and order one of their custom "wiring harnesses" for
you car. Almost all factory stereos these days have
a manufacturer specific wiring harness that just plugs
into the back of the stock receiver. Many stereo add/in
places will just cut this harness off and custom tap all
the wires. Leaving you with a huge mess if you want to
put a different stereo in, or put the old factory stereo
in to sell the car. The Crutchfield wiring harnesses
plug right into the factory plug. So you just (in the
comfort of your home) wire your new stereo to the 
harness, and then go out to your car, follow the Crutchfield
supplied instructions for removing your receiver, and
drop in the new one, plugging in your new harness.

I warn you, if you cut off the factory stereo plug, you
will regret it. Either because you'll spend two hours
hunting and pecking to find out which speaker wire is which,
or because later you'll want to pull the stereo out and 
not remember which wire is which. Buy the harness
from Crutchfield (or somewhere) they are about $10.

Replacing a receiver is very easy. If you are careful and
prepared, you can do it in just a few hours, and most
people who can operate a screwdriver should have no 
problems.

2) Replacing the speakers

The next most difficult task is replacing the speakers.
In some ways it's often easier than the stereo, because
you usually don't have to disassemble any parts of a
dash board. Get the "Hayes" car maintaniance manual for
your car. They will explain (usually with pictures) 
exactly how all the speaker grilles come off. I think the
crutchfield harness booklet might also explain this
(I don't remember). 

If you are just replacing the speakers with better ones.
(i.e. not adding any subwoofers or tweeters) then this
is really easy. You just check the Crutchfield fit guides
for your car and the speaker you want. Then you find the
best price on that speaker. (or you just buy it from
Crutchfield to support their great catalogs) Make sure you 
get the polarity of the speaker wires right when you put
them back in. With some speakers it won't matter, with
some it will, but it's better just to get it right.

If you are adding tweeters or a subwoofer then you will
have an "installation" issue and a "wiring issue" for that
device. I'll cover custom wiring and installation below.

For sound fidelity reasons, tweeters should be mounted 
somewhere with direct "line of sight" to all the car's
occupants. This is because high frequency sound is 
directional and reflects off just about anything. The front
window/door posts is a good location. Factory tweeters
usually mount on the "inside" of the side rearview mirror
location, while aftermarket ones are usually mounted
slightly higher on the post. Check for a "factory" mounting
molding. Recent subarus have a factory tweeter package and
you may be able to get just the molding. (or you can
just install the factory ones)

Subwoofers can be mounted just about anywhere. Low frequency
sound is not very directional. In fact, the human ear has
a hard time distinguishing the source location of low
frequency sound. common places to mount subwoofers are
under the seats, or in the trunk. If you put it in the
trunk make sure it fires forward. Also make sure that 
whatever you mount the subwoofer to is an integral part of
the car. If you don't, you'll eventually have an extremely
annoying rattle with every bass hit.

3) CD player changers, amplifiers, and stuff

These are the most difficult pieces that you'll install,
along with tweeters and subwoofers. This is because you
have to add additional wiring, and you have to find a 
convinent place to mount the device.

Amplifiers are tricky, because just about anywhere you
put them will require you to rewire ALL the speaker wires.

*** Installation Issues:

Just remember that while anything you add to the car is
going to add value, anytime you cut the visible stock 
car parts you will potentially reduce value, so if you 
are going to alter a visible part, think twice, or three
times about what you are going to do, what it's going
to look like, and realize how irreversable it is. (i.e.
if you are going to drill a hole in the trunk below the
carpet, it's not as big a deal as if you are going
to drill a hole in the top of the dashboard to run a 
tweeter wire.

Any time you drill through metal (which isn't as big a
deal as many of you would think) you want to make sure
that you put silicon sealer in the hole before you
put the screw in. Any place that you cut through metal
you are exposing a non-galvanized part of the car. Even
if it seems to be a completely interior part, it will be
suceptable to rust. Make sure you puts lots of silicon
sealer on and dip the whole screw into silicon sealer
before you insert it.

Take a good look at what is on the other side of where
you are drilling. It helps to have full body schematics.
Make sure that you are not going to drill and find out
you just put a hole in the gas tank. 

Speaking of gas tanks. Any time you are going to be drilling
aside from trying to go through the trouble of completely
emptying (with a syphon) the gas tank and then letting
it dry. The safest thing to do is to FILL THE TANK. If you
have any doubt about whether or not you'll be going into the
tank you really probably shouldn't be doing what you are
doing. However, to be on the safe side, get a full tank
before you start any of this stuff. Liquid gasoline is not
explosive, but the fumes are, the more gas in your tank, the
less fumes.

*** Wiring Issues:

When you are placing wires you want to think about:

1) is this wire going to be seen
2) is the wire going to be crimped and possibly broken
because of where it is
3) with speakers, CD player, or HAM radio wires: am I 
going to be causing interference because of the
wire placement? 
4) Is there a ferrite core on the
power wires to keep them from picking up noise from
the car alternator? Usually CD changers and HAM 
radios come with these installed on the power wires
already.
5) Is the source of all this power going to handle what
this new stuff is trying to draw? Check fuse ratings,
subwoofers will often require "high power capacitors"
to prevent headlight dimming when the bass hits.

Usually factory speaker wires run down the side channel
of the interior. It's a plastic runner which covers up
each side of the carpet and holds it to the ground. The
runners are usually very easy to remove with just a few 
screws. If you are just installing one set of wires, then
you probably will be fine putting them down one of the
runners. Think about which side is more convinent
for the "trunk end" of your installation. It's usually
much easier to have wires come out of either side of the
front dash than it is to get wires to "switch sides" in
the trunk. 

If you are installing quite a few wires, or you are 
installing thick "gold" speaker wires, or you are 
installing ham radio antenna wires, or just about anything
that is more than just a few standard wires thick, you
may want to think about putting the wires somewhere else.
Remember that the side channel is going to tighten down on
the wires and if you put alot of them in there, either the
moulding is going to crimp some of them, or the moulding
isn't going to fit right and you're going to notice it.
Often times wires will "fall" out in places along the 
side channel if you put too many of them in there.
The stock speaker wires in an old Chevy Celebrity had
did this. If there is plenty of room, but the speaker
wires like to fall, then take the runner off and find
some way to affix them up there. I suggest either
double sided tape under them, or better yet, plastic ties
if you can find something to tie them to.

Use as many wrap ties as you can. You really don't want a
big jumble of cables under there. Even if you route them
cleanly, if they are just laying under the carpet somewhere,
they will often work their way into bad places. Try to
wrap-tie the wires every foot or less, and if possible 
wrap tie them to something to keep them in place.

If you can't fit them in the side channel, then you'll
likely put them down the center channel. Which means
you'll need to remove the front seats, and lift the 
carpeting. This starts to get more tricky than most people
want to do, so think about whether your installation is
going to require this before you start removing 
stock components. It's always a good idea to remove the
negative battery cable any time you are doing something
like this. I never have, but then again, I've not done
this in cars with ABS, airbags, and other computer systems
which can be sufficiently confused by unplugging things. 
Just be careful to find the wiring connectors which connect to the
seat belt buckle. They tell the car if you have your belt
buckled. In most cars the buckle is attached to the seat
and not the floor. 

At any rate, taking the seats out is usually pretty easy.
Just two or four big bolts, the wiring connector, and they
come right out. Take care not to do this outside while it's
raining, other than that you should be okay. You'll
also need to decide if you need to take all the seats out
or just the front ones. A good place to wire things in
my experience is down the "foor side" of the center
channel. You can run them right from the center of the
dash or under either front seat to the center, then down
the center. In front of the rear seat you will probably
want to run them towards the side of the car, following
the "corner" of the seat bump and the floor. (by the
seat bump I mean the place where the metal body of the
car is raised where you attach the rear seat cushions.)
Then you can probably just use the same entry to the trunk
that the stock speaker wires use there along the side.

Back up near the front of the car, a good place to get 
power for these additional devices is to use "extra-unused"
fuse slots in the passenger fuse compartment. It'll save
you from having to put the wires through the firewall (the
part of the car between your feet and the engine 
compartment) Again, look at diagrams of the fuse box if you
have them and figure out how to power and use one of the
unused slots (if you have them). Some high power devices
like subwoofers and HAM radios recommend that you go
directly to the battery as a source of power. I'm not so
fond of doing this. Although you can go to the in-hood
fuse box instead of the one in the passenger compartment.

Again, make sure you _TEST EVERYTHING_ before you start
putting carpet back down and seats back in. You'll be very
mad if you find out you got everything back together 
saftely just to have to take it all apart again because
left is right and right is left.

This means:

1) test right and left balance
2) test front and back fading
3) test each component speaker (turn up the treble and
make sure the tweeters are working and that they
too are "right/left correct")
4) make sure the subwoofer and subwoofer crossover is
installed correctly. Make sure you hear a bass hit
whether it comes from the right or the left channel.
5) test all operation of the CD changer (although usually
if it works at all, it's working completely)

Enjoy your new stereo. :)