Sound Advice - Article 3

In this article I'll be talking about installing your after market head unit and the tools required to accomplish it.

In the last article we talked about upgrading your head unit and whether or not it was necessary. If you have decided to purchase an after market head unit then you'll either have to pay a professional to install it or do it yourself. To install a basic in dash head unit and connect it to your factory speakers will take a pro maybe an hour. The going shop rate is  *about*  $45.00 per hour, so you'll be spending at least that amount plus any taxes and needed installation pieces.
    Ask yourself this question before you decide on attempting the install yourself;  "Do I feel comfortable working with automotive electrical systems?". It's very unlikely that you'll hurt yourself but you could damage your car if you are not careful. An improperly protected wire can short and cause a fire; fires and automobiles don't mix. If you don't have a clue what electrical circuits are or don't feel comfortable working with electricity then consider paying the pro to do it. The job will be done properly  (in most cases) and the store will be liable for damages. Another point to consider is with regards to the warranty of the component you buy. Some warranties will be void or the term will be reduced if they are not installed by a certified installer.  O.K. if you haven't been frightened off and still wish to try the installation yourself; read on. P.S the usual disclaimer about " You do this at your own risk and the writer assumes no liability" goes here....

Tools needed

    You'll need some tools before you try and install any component.

    The above tools will at least get you started. Once you get more involved then your tool inventory will expand greatly. Things like drills, circular saws, routers, jig saws, soldering irons etc. will make custom installs easier but it takes time and money to get these items.

    Removing the factory head unit

I'm most familiar with first generation cars. There may be some differences in the following instruction to second generation cars. You should take inventory of your present system before removing your old unit to determine if you need to buy a mounting kit or not, or whether  you feel skilled enough to fabricate your own. The opening in  the first generation cars is a double ISO size. ISO stands for "It's Soon Out", just kidding....It's actually a standard that has been adopted by the industry. Sometimes these are referred to as DIN openings but they are slightly smaller and are often found on European cars (it's a German standard).  O.K. so this double ISO opening can have a few different configurations. 1) The top has a radio and the bottom has a little pocket for storing change 2) The top has a radio and the bottom has a tape or CD. 3) The top has a radio and the bottom has an EQ. The important thing to look  for is whether or not the bezel, that surrounds the radio, has a  bar to separate the components. If it does and you are putting in a single ISO unit in the top then you can either put the pocket thingy in the bottom, leave the other factory component installed  (non functioning) or buy/make  a block off plate to cover up the opening. If it doesn't have the separator bar, and you are only installing a single ISO radio, then you will have to buy an installation kit or fabricate your own to cover the hole and support the radio. i.e. you are not going to be able to install a single ISO unit in the double ISO opening without a kit of some sort. An alternative would be to buy a factory bezel, with the bar separator, either from a scrap yard or the dealer. If your replacement radio is ISO and a half ( or DIN and a half)  then you'll likely be fabricating your own cover. A double ISO replacement should fit the bezel that has no bar and can be made to fit the ones that do have a bar (cut and file).
    Make Sense???  O.K.  Let's continue....
    The first thing to do is removal the bezel around the factory head unit. It is held in place by four spring clips. GENTLY pry the bezel using a flat screwdriver. You must pry gently or you'll mark (actually leave small indentations) in the black center dash portion. Once it's removed you'll see four screws that hold the radio in; remove these and the head unit and brackets will pull forward. pull out the antenna cable and unplug the wire connectors. The old head unit should now be fully free and can be disposed of any way you see fit. I removed the front of my old one and used it as a fake radio to put in place of the pullout unit when I leave the car.
    Now you have to connect the harness from the new radio to the factory wiring. You should have a wiring diagram with your new radio that will list the connections. Usually you will need +12V constant, +12V ignition, ground, maybe a dimmer control and power antenna wire. If you are using a power amp then you will likely need a remote turn on connection, from the radio, to the amplifier.  If you plan on using the factory speakers (yuckkkkk!) then you can either splice into the wimpy factory wires or run thicker stuff yourself. That way  when you upgrade your speakers the wiring is already inplace. So, how do we connect the wires from the new radio to the harness from the old radio? Well, there are a couple of options. You can buy a wiring adapter that connects the factory sockets to the new radio's harness. Or, you can splice directly into the factory harness using crimp connectors, the trick is finding the correct wire! This is where the multi meter comes in handy.

Setting up the multimeter

    I'm going to assume that you have never used a Multimeter before, if you have, skip this section.
First things first, assemble the meter. Put the probes in the CORRECT holes in the meter. Some meters will have three holes. One is "usually" for the red probe and the black probe could go into one marked for Current or one marked Volts/Ohms. It is the latter we are interested in. If there are only two holes then it's simple; red to (+)  black to (-). Now select DC volts with the dial and choose a scale of up to 20 volts or so. If you pick a scale that is too low then when you find a wire with +12v you will peg the needle and possibly damage the meter.

Using the multimeter to find the appropriate wires:

    So now we have a meter set up to read volts and have a scale chosen to read 12 volts safely. The smoke, ummm, fun now begins!
    Take the black probe and connect it to a good metal piece on the car frame (the metal behind the radio is a good choice). Now, with the red probe we are ready to hunt for the wires that have both switched and continuous +12V on them. Grab one of the factory connectors and start probing the metal contacts at the end. When you find one that reads about +12V take a piece of masking tape and mark it +12V continuous. This will be connected to the appropriate wire on the new radio which  is usually yellow or red and has a fuse connector. It's likely labeled +12V or something. Next up is locating the +12V that comes on with the ignition. Put the keys in and turn it to ACC or START. Now start probing again until you find another wire that reads +12V. To verify it is switched +12V, turn off the key and remove it. The meter should drop to 0V. If it does then it is a switched source, if it doesn't then it is not. If your new radio has a wire for a dimmer control then you'll need to find that next. Turn the headlights on and start probing again but with each attempt turn the dash dimmer knob. You'll  know when you've found the right one because the voltage reading will VARY when you turn the dimmer knob. Mark that wire also. You won't have to worry about a ground because you can directly attach the ground from the new radio to a good point on the car frame (there are lots of handy bolts behind the side panels of the console).
    If you want to use the factory speakers or just the factory wires then finding them is the next task. The procedure is different from the one we used to find the +12V wires. You'll need to first change from Volts to Ohms with the knob on the meter. Choose a scale setting to read up to 10 Ohms or so. Take the two probes and touch the tips together, the meter should move to the right and read 0 ohms. If it is off slightly there is often a small screw that can be used to "zero adjust" the meter.
    "Most" factory speakers will have a nominal impedance of 4 to 8 ohms so we will use this piece of information to hunt down the correct pairs of wires. Take one of the probes and put it in one of the factory contacts. Now start probing with the other probe, "usually" the speaker wire pairs are next to each other and towards the outside of the connectors so start probing close to the other probe. You'll know when you've found a pair because the meter will move and read somewhere between 4 and 8 ohms. Once you've found a pair mark them. Continue probing until you've identified all the pairs.  Now take that 9 volt battery and connect a piece of wire to the( +)  and one to the( -) . Put one of the wires into one of the  two contacts that you think are a pair and with the other wire TOUCH  the other contact. You should hear a pop from a speaker. Locate which speaker is popping  by tapping the contact with the wire. The speaker will pop each time the wire touches the contact. WARNING! Do NOT keep the 9V battery hooked up for long periods of time to a speaker! Just momentarily touch it! You could damage the speakers voice coil if you fail to heed this warning!  Label the pair with tape (e.g. front left)  and continue until all the pairs are identified.  Now, we have to determine, on each pair,  which is + and which is -. Look for clues! Is one wire solid in colour and the other striped? If you can pick up a pattern it doesn't matter which you pick to be positive or negative as long as you maintain the pattern. For example if each pair has a solid colour and a striped wire then either can be  chosen to be + or - as long as you don't change your choice. If you do change then some speakers will be out of phase with others and the sound will suffer. You can use the 9V battery to check but you will likely need a friend to assist. Take a speaker pair again and repeat what we did previously i.e. make the speaker pop. Have your friend watch the speaker cone (this might not be an easy task if it's behind a grille) as you touch the wire to the contact. Note which way the cone moves when you "pop" it. You want all the speakers to move either toward you or away when you "pop" them. You have to keep the same polarity with the battery on each pair. When the speaker moves note which wire the (+) of the battery is connected to. Is it solid or striped?  If all of the cones move toward you when you touch the (+) of the battery to a solid colour then choose the solids as (+).
    I prefer to run new heavier gauge wire to each speaker. This is more physical work but you don't have to worry about finding the factory wires and the system will be ready for future upgrades. The worst part is trying to get the wire through the rubber tube that connects the door to the frame. I'll leave that up to you to curse and swear over! Hint: pop the tube out at each end then pop it back in again after you have pulled the wire through the tube. Use 12 to 16 gauge wire to help with getting all of the available power to the speakers. After market speaker wire is usually marked to differentiate (+) and (-) so it's easy to connect to the appropriate head unit connections.  You might  want to plan for the future at this point.  If you know you will be adding an amplifier(s) later then run sufficient wire to connect the speakers to it (the amp).  You don't want to go through the trouble of running wire, then, have to either, run more later or splice  because you didn't leave enough to reach the amp. You can coil the excess up under the console or dash. When you add the amp, at a later date,  you just disconnect the speakers from the radio, pull out the excess wire and re-route to the amp.
    I believe that's it for finding the wires. Now we connect the new radio to the now identified factory harness wires.

Joining the wires together:

Before we can join any wires we have to first cut them from the factory harness. Use the cutting section of the crimp tool and cut the wires about 2" away from the factory connector. By cutting here you can always reconnect the factory system at a later date. This is handy if you ever sell  the car  and want to remove the after market system.
    If you know how to solder then that is the strongest  and most secure method to use, just be sure to use heat shrink to protect the connection. An easier method is to use solderless crimp connections. For joining the radio wires you'll be using the red "butt" connectors. These are little tubes, which, when crimped at each end will permanently join the two wires together. You put the new wire in one end and the factory wire in the other and squeeze. Presto! You've got a joined wire! You can also use "bullet" connectors which are similar to the "butt" connectors except you can easily pull the connection apart to remove the radio at some point. You  basically crimp a bullet on each wire and then insert each into a special tube to join the two.
    Avoid just twisting the wires together and using electrical tape. The tape, after time, will become a sticky mess and will likely slide away from the join leaving exposed wires.
    To use the crimper first strip about 5 mm of insulation from each wire to be joined. You can use the strip portion of  the tool to do this. It's often close to the handle and will likely be labeled to show different gauges of wire that can be stripped. Now take a butt connector (or bullet) and stick one of the wires in the end, you want the end of the wire to be about half way. Get the crimper and look at the end of the tool. You should see three crimp sections each marked with a coloured dot. Simply use the section that is colour coded to the connectors you are using. In our case you'll be using the red section. Open up the crimp tool and put it over the butt with the wire in it. You want to crimp it about half way between the middle and the end of the butt. If you crimp it to near the end then you are only crimping the insulation and if you crimp it to close to the middle you'll have difficulty getting the other wire in. Now put the other wire in the other end and crimp it it the same manner. After you have both wires crimped together it is important to give them a tug to check the strength of the connection. If one wire pulls out then you'll have to cut the butt connector from the other wire, re-strip it and use another butt connector to try again. Repeat for all wires identified earlier, including the speaker wires. If you are running new speaker wire and are using a larger gauge then you will likely need to use the blue connectors. This can pose a problem when you come to join the wire to the relatively thin speaker wire coming out of the deck. In this case strip twice as much wire from the thin wire and then bend the stripped portion in half so that you have effectively doubled the gauge of the wire. You should now be able to crimp the thicker speaker wire and thinner deck speaker wire together using a blue connector. At the speaker end you can either a) solder the new wire to the speaker terminals b) crimp a female spade connector on and slide it over the speaker terminals or c) cut the factory connector off  and splice using the butt connectors.
    O.K. You should now have all your radio's wires connected to the factory harness and/or new speaker wires. The only task now is to install the radio in the dash opening.

Installing the new radio in the dash opening:

Most radios manufactured today will come with a metal sleeve to facilitate ease of installation. If  you are installing a single ISO unit and have a bezel with a bar then installation is relatively easy. Simply slide the sleeve through the bezel from the front until it sits flush. You'll  notice that the sleeve has numerous cutouts around the perimeter with small tabs in them.  These tabs are designed to be bent out so that the sleeve is secured in the opening, in this case the bezel. So, from the rear bend up some of the tabs so that the sleeve doesn't move at all in the bezel. As I mentioned earlier if you have the bar in the middle of the bezel, and, don't plan on installing anything in the lower half then you'll have to either buy a block off plate or fabricate your own using plexiglass. It's a relatively easy thing to make. First, cut some plexiglass to size (it has to be bigger than the opening). Second,  paint it black (trim paint from Canadian Tire works well). Third, either glue it to the front of the bezel or from the rear, it's your choice. You might want to try an epoxy glue or something that will bond different plastics and has good strength .As an  added bonus the block off plate is a great place to install an after market gauge or two e.g. boost gauge. If you don't want a block off plate then you can put it in the storage pocket or leave the old lower component installed but non functional. In this case you will have to re-install the component using the brackets you removed earlier. With no bezel bar you'll have to use an installation kit, available from most car audio stores or fabricate your own once again using plexiglass. It's a lot more difficult to make this plate as you have to cut the hole in the upper half for the sleeve. The opening takes up most of the room and leaves a thin border that can break easily if you are not careful. A double ISO unit should fit the bezel the same way as the single ISO unit does, unless you the one with a bar. In this case cut the bar out and carefully sand/file the edges.
    I think we've covered all options now. You now have a bezel with a metal sleeve firmly held in place with those tabs. Now, snap the bezel back into the dash opening.  Pull the wiring harness, along with the antenna wire, through the metal sleeve  and  connect them to the radio. You might need an adapter for the antenna wire depending on the size of it. It should fit nicely into the radio. If it is loose or will not fit in the hole then you need the adapter which is available from most places, including Canadian Tire. Now before you slide the radio into the sleeve; test it out. Turn the key to ACC and turn the radio on. Either pop in a CD or tune to a station. Exercize the balance and fader controls and make sure the sound comes out the correct speaker. If it doesn't you've likely got the speaker wiring wrong. If you have no sound then you'll need to do some investigating. Does the display light up and can you tune the radio? If not then it's a wiring problem in the power connections. Recheck the connections and the crimps, you may have a bad crimp or a wrong connection (including a bad ground). If everything checks out ok then slide the radio onto the sleeve until it locks into place. The next step is up to you to decide whether or not you think it is necessary. It is "recommended" that the radio be supported with a back strap. However, with the installation in my car and the others I have done I don't believe this  required in all cases. The metal sleeve distributes the weight over a bigger area and the bezel clips are fairly hefty. If you decide you need it then remove one of  the console side panels and bend the strap (supplied with the radio) until you can screw it to a supporting brace or something. You'll likely decide in short order that it's more trouble than it's worth.
    Well, that should be it! Sit back and enjoy! You've just installed your first after market component! Remember, please email me if you find these articles useful or not and for any corrections or obvious mistakes (spellling/grammer not included :-) ). If, you attempt this installation and run into problems let me know and I'll see if I can lend some insight.