C4 '96 Full Install Part III
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Safety Car
Joined: Sep 2006
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From: Pasadena CA
C4 '96 Full Install Part III
Part I Here
Part II Here
The write-up has taken almost as long as the install
Recap - speaker boxes and front mids were in, rear speakers were in and wired. Loom was wired to receiver loom and joined to HU loom. Onto wiring the amp
AMP WIRING
I placed the MDF board cut for the amp and placed it under the carpet and first layer of soundproofing material behind the passenger side storage lid. I put the carpet over the board and then the amp on top. I initially screwed 2 of the mounting screws straight into the carpet and the board beneath so I had a visual to get the amp lined up right. Once I had it positioned over the holes in the board, I screwed all 4 mounting screws through the amp, carpet and board beneath. This thing was not going to move!
Next was the easy part - feeding the rear speaker wires to the amp, getting nice runs under the carpet and along the back of the storage lids. Then I ran some more speaker wire for the fronts that would go from the crossovers to the amp. These went under the carpet into the storage bin. There are places to tuck this wiring, you just have to fiddle around and practice laying the carpet down and checking you have the wire length right. I wrapped some tape around each of the 4 speaker wires, forming a small tab, and wrote their speaker designations on each tab, like FR, RR, etc, so I could easily identify the wires later on (they all look the same!).
I won't go into removal of the dash bezel and center console - other posters have shown this just fine and it's a lot simpler than you think. Once you've figured out where the screws are, you actually don't even have to remove the center air vent or the gearshift ****. These plastic pieces will bend to a degree, but you still have to be careful not to break anything.
Removing the passenger seat is even easier - take out seat bottom, slide seat forward, undo rear bolts, slide seat backward, pop 2 little plugs holding 2 plastic trim pieces at the front of the rails, then 2 front seat bolts, disconnect power motor coupling, then lift up and it's out! I didn't bother with the driver's seat. I spent a lot of time either sitting in the drivers seat and fiddling with the HU, or kneeling in the passenger area with my head in the storage bin!
With the seat out I started feeding the wires from the storage compartment to the front of the car. This means pulling up the carpet over the rear wall and locating the large grommetted hole under there that is designed just for the job. When I pulled mine back I found this:
This solved the mystery of how the JVC 12-CD changer that came with the car sends its signal to the HU. Here is its transmitter and a bunch of antenna and control unit wiring behind the carpet. Actually whoever fitted this did a really nice job. The wire was neatly bundled and the installer had even drilled and attached his own ground bolt into the metal wall. This it turned out saved me a headache after I found my ground lead was an inch too short from reaching the seat bolt - my planned grounding point. I used this one for the amp ground instead, again running that wire from the amp, under the carpet, into the rear storage bin then out through the hole in the wall.
A fundamental aim was to keep power and ground wires separate from signal-carrying wires as much as possible. The idea was to prevent noise and other nastiness you don't want. So the plan was to run the power wire over the driver side sill, the ground down to the passenger seat post, and the HU loom, antenna lead and RCA wires down the middle, over the passenger side of the tunnel.
Here's where I made another minor mistake, which was just a part of figuring out how these C4s are put together. In my haste to get under the carpet of the tunnel, I pulled back part of the carpet from where it is glued to the plastic panel - you don't need to do this! Just take off the few bolts holding the plastic part of this side panel to where it meets the center console and another that's up behind the dash bezel. The plastic and carpet all come out as one piece, with a bit of jiggling. I later stood on this panel and accidentally broke off the part that attaches to the dash. The worst part though was trying to glue the carpet back onto the panel - it was a bitch to get right as the carpet had either shrunk or was never cut to shape correctly in the first place.
Pulling back the carpet - whoops
Next was hooking up the wires from the front speaker boxes to their respective crossover boxes, and then the crossovers to the amp. I had already decided on where to place the crossovers - they were too big to go in the speaker boxes, too vulnerable to water damage behind the door panels and too big to go most other places except behind the seats.
Crossover wiring
I had read this particular design is a pain to connect, but I didn't really believe it until I tried. You need to feed the wires through the holes in the case first, then to the base unit, which has fiddly little cross-head screws. This seems easy when you're only dealing with one side, but once you get both sides (input and output) hooked up, and need to make adjustments to the wires, you'll be cursing the designers like I was.
Feeding front wires
Part of the fun with the install is figuring out how to hide the wiring. I absolutely did not want wires to show, as much as possible anyway. Whatever wire was exposed I planned to use black split loom to cover it. Here's where you need to make double sure your wire lengths are correct. You can easily end up several inches short once they've been curved and tucked around things. I always measured with a flexible measuring tape, then overestimated by a couple of inches, then added a few more for luck. Even doing this there was an occasion where I had to re-cut and resolder a connection because the first one was too short.
Another thing I tried to do was keep the lengths for the front speaker wires as similar as possible. I guessed that the nearer they are in length, the better chance you have for synchronizing signals. I have no idea if this is true, it just sounded right to me!
With the front speaker wires hooked up and the routes figured out it was time to sort out the power lead. This involves removing a body panel to access the battery, figuring out the routing from the interior to the engine compartment and figuring out a place and means to attach the fuse.
One of the little extras you need to buy is a battery post extension so you can attach your amp positive lead directly to the battery. Hopefully you have a nice thick power cable such as the 8 ga one that came in the kit. 18 feet was plenty to let you run it wherever you want.
Aftermarket battery post terminal next to stock one
I went looking for the GM one but ended up with this generic one from Autozone. It is the correct thread but is too long, so instead of delaying the install again, I used 3 washers to fill the gap and hold everything down and used it anyway. It sticks out a bit but still fit ok in the battery compartment. I later had some trouble getting an intermittent connection with this, so I'd recommend getting the correct one for GM.
Here's the hole that goes from the interior and through the door hinge area. In the picture it is directly above the rubber accordion going into the door. This hole already had a rubber grommet that I was going to use in the same way as I did with the ones in the rear speaker boxes. Unfortunately I pushed it in trying to get it out and it disappeared into the black abyss in there. I never figured out a way to retrieve it. Oh well, not much rain in Socal...probably be ok.
Running amp power lead
The power lead was routed under the rear carpet, behind the drivers seat then along the top of the drivers side sill. The speaker wire was routed along the bottom of this sill and never touched the power wire. The lead then went up and out the hole shown above.
View looking back
power wire routing to battery
Starting to look a little less scary now. There was another pre-existing hole in this metal structural part. No drilling required. I ran the wire through and then cut two lengths of split loom to cover the wire each side of the steel wall.
Here's where it gets fun. You need to remove the body panel that covers the battery. Now if you've already changed a battery you're probably intimate with this part of your car. I was not, and I have to say this was one of the biggest PITA moments of the install. There are some very simple bolts to remove in the rear part of the front wheel well, one on top and then one underneath. It was getting to the one underneath that caused me headaches. I ended up having to remove part of the actual sill so that I could bend it down enough to get some pliers in there to get to the last bolt. I think it wasn't necessary to do this in the end ( I had this panel on and off more than once during the install), but at the time seemed like one of those extra little things that you weren't anticipating.
Anyway, the idea was to locate a place to attach the fuse holder and to slide the battery part of the way out in order to reach the positive terminal.
I examined this area below, next to and above the battery and could only see one good place to mount the fuseholder. There is a bulkhead/ firewall here that I wanted to drill. I just couldn't figure out a way how I could get a drill, or any power tool, in that little space. So in the end I decided to just glue the thing to the steel, and hope for the best.
Battery area, panel removed
In the bottom right of this pic you can just make out the top of the fuse holder. I measured out my wire lengths from fuse to battery, then glued the holder to the metal (after cleaning it) with silicon adhesive. I then taped it down for good measure. I let it dry overnight, then came back and connected everything up. Once the wires were attached I used more tape to make it as waterproof as possible. The last part was soldering the gold-plated ring terminal that came with the kit to the wire, attaching the new terminal post to the battery positive, and then the wire ring terminal onto the new batter post. Push the battery back into place, check connections again, then bolt up the panel.
It's also a good time to clean out your battery area. The bottom of mine was covered with dried up deposits from a previous battery leak.
Buttoned up
One more piece of split loom protects the wire and helps keep it stealth!
HEAD UNIT INSTALL
I followed StealthLT4's advice and decided to run the HU stuff in from the side rather than underneath. I had the loom already up there. Next was the antenna lead and RCA's. My kit only came with one set of RCA leads. I wanted another set that was decent quality but not a rip-off price. I eventually found some nice Sony ones in Target that were gold-plated, and priced well.
I had more fun with my head in the storage bin running the antenna lead extension (10ft long from Installer.com) and the RCA's. I managed to get the RCA's to come out the side of the bin and stuffed under the carpet with the speaker wires, then out to the amp.
Amp with initial connections
Here's how things were looking from the back of the car.
Passenger side tunnel showing wiring routes
In this pic you can see the routing for the HU loom (multicolored), RCA's (white and green) and antenna (black). Also the rough position for the passenger side crossover. Later I discovered that I had mounted this crossover a little too low, once the seat was back in. The metal part of the seat frame will hit the crossover if the seat goes all the way back. Driver's side position was fine because, of course, I didn't remove the driver's seat!
Amp from front of car
I still had some work to do hiding wires. I was starting to get ideas about how to do this.
I was ready to fire up the amp and see if everything worked. I connected the tweeters to their respective inputs on the crossovers. The wires were too short but I just wanted to hear everything at this point. I brought out the HU and connected everything to the back with the unit sitting on the center console. I then attached the negative lead to the amp where I had left it disconnected, and then connected the battery negative terminal.
Amp powered up
Everything worked first time!
This is why I chose this HU. I wanted the red lights to match the stock lighting, while it wasn't too flashy that someone might shove a brick through my window to take it.
I found the motor antenna went up and down at the right time (when Tuner is selected), there was sound coming out of all the speakers, and I started to familiarize myself with the settings on the HU
Final part - Installing HU and door tweeters
Part II Here
The write-up has taken almost as long as the install
Recap - speaker boxes and front mids were in, rear speakers were in and wired. Loom was wired to receiver loom and joined to HU loom. Onto wiring the amp
AMP WIRING
I placed the MDF board cut for the amp and placed it under the carpet and first layer of soundproofing material behind the passenger side storage lid. I put the carpet over the board and then the amp on top. I initially screwed 2 of the mounting screws straight into the carpet and the board beneath so I had a visual to get the amp lined up right. Once I had it positioned over the holes in the board, I screwed all 4 mounting screws through the amp, carpet and board beneath. This thing was not going to move!
Next was the easy part - feeding the rear speaker wires to the amp, getting nice runs under the carpet and along the back of the storage lids. Then I ran some more speaker wire for the fronts that would go from the crossovers to the amp. These went under the carpet into the storage bin. There are places to tuck this wiring, you just have to fiddle around and practice laying the carpet down and checking you have the wire length right. I wrapped some tape around each of the 4 speaker wires, forming a small tab, and wrote their speaker designations on each tab, like FR, RR, etc, so I could easily identify the wires later on (they all look the same!).
I won't go into removal of the dash bezel and center console - other posters have shown this just fine and it's a lot simpler than you think. Once you've figured out where the screws are, you actually don't even have to remove the center air vent or the gearshift ****. These plastic pieces will bend to a degree, but you still have to be careful not to break anything.
Removing the passenger seat is even easier - take out seat bottom, slide seat forward, undo rear bolts, slide seat backward, pop 2 little plugs holding 2 plastic trim pieces at the front of the rails, then 2 front seat bolts, disconnect power motor coupling, then lift up and it's out! I didn't bother with the driver's seat. I spent a lot of time either sitting in the drivers seat and fiddling with the HU, or kneeling in the passenger area with my head in the storage bin!
With the seat out I started feeding the wires from the storage compartment to the front of the car. This means pulling up the carpet over the rear wall and locating the large grommetted hole under there that is designed just for the job. When I pulled mine back I found this:
This solved the mystery of how the JVC 12-CD changer that came with the car sends its signal to the HU. Here is its transmitter and a bunch of antenna and control unit wiring behind the carpet. Actually whoever fitted this did a really nice job. The wire was neatly bundled and the installer had even drilled and attached his own ground bolt into the metal wall. This it turned out saved me a headache after I found my ground lead was an inch too short from reaching the seat bolt - my planned grounding point. I used this one for the amp ground instead, again running that wire from the amp, under the carpet, into the rear storage bin then out through the hole in the wall.
A fundamental aim was to keep power and ground wires separate from signal-carrying wires as much as possible. The idea was to prevent noise and other nastiness you don't want. So the plan was to run the power wire over the driver side sill, the ground down to the passenger seat post, and the HU loom, antenna lead and RCA wires down the middle, over the passenger side of the tunnel.
Here's where I made another minor mistake, which was just a part of figuring out how these C4s are put together. In my haste to get under the carpet of the tunnel, I pulled back part of the carpet from where it is glued to the plastic panel - you don't need to do this! Just take off the few bolts holding the plastic part of this side panel to where it meets the center console and another that's up behind the dash bezel. The plastic and carpet all come out as one piece, with a bit of jiggling. I later stood on this panel and accidentally broke off the part that attaches to the dash. The worst part though was trying to glue the carpet back onto the panel - it was a bitch to get right as the carpet had either shrunk or was never cut to shape correctly in the first place.
Pulling back the carpet - whoops
Next was hooking up the wires from the front speaker boxes to their respective crossover boxes, and then the crossovers to the amp. I had already decided on where to place the crossovers - they were too big to go in the speaker boxes, too vulnerable to water damage behind the door panels and too big to go most other places except behind the seats.
Crossover wiring
I had read this particular design is a pain to connect, but I didn't really believe it until I tried. You need to feed the wires through the holes in the case first, then to the base unit, which has fiddly little cross-head screws. This seems easy when you're only dealing with one side, but once you get both sides (input and output) hooked up, and need to make adjustments to the wires, you'll be cursing the designers like I was.
Feeding front wires
Part of the fun with the install is figuring out how to hide the wiring. I absolutely did not want wires to show, as much as possible anyway. Whatever wire was exposed I planned to use black split loom to cover it. Here's where you need to make double sure your wire lengths are correct. You can easily end up several inches short once they've been curved and tucked around things. I always measured with a flexible measuring tape, then overestimated by a couple of inches, then added a few more for luck. Even doing this there was an occasion where I had to re-cut and resolder a connection because the first one was too short.
Another thing I tried to do was keep the lengths for the front speaker wires as similar as possible. I guessed that the nearer they are in length, the better chance you have for synchronizing signals. I have no idea if this is true, it just sounded right to me!
With the front speaker wires hooked up and the routes figured out it was time to sort out the power lead. This involves removing a body panel to access the battery, figuring out the routing from the interior to the engine compartment and figuring out a place and means to attach the fuse.
One of the little extras you need to buy is a battery post extension so you can attach your amp positive lead directly to the battery. Hopefully you have a nice thick power cable such as the 8 ga one that came in the kit. 18 feet was plenty to let you run it wherever you want.
Aftermarket battery post terminal next to stock one
I went looking for the GM one but ended up with this generic one from Autozone. It is the correct thread but is too long, so instead of delaying the install again, I used 3 washers to fill the gap and hold everything down and used it anyway. It sticks out a bit but still fit ok in the battery compartment. I later had some trouble getting an intermittent connection with this, so I'd recommend getting the correct one for GM.
Here's the hole that goes from the interior and through the door hinge area. In the picture it is directly above the rubber accordion going into the door. This hole already had a rubber grommet that I was going to use in the same way as I did with the ones in the rear speaker boxes. Unfortunately I pushed it in trying to get it out and it disappeared into the black abyss in there. I never figured out a way to retrieve it. Oh well, not much rain in Socal...probably be ok.
Running amp power lead
The power lead was routed under the rear carpet, behind the drivers seat then along the top of the drivers side sill. The speaker wire was routed along the bottom of this sill and never touched the power wire. The lead then went up and out the hole shown above.
View looking back
power wire routing to battery
Starting to look a little less scary now. There was another pre-existing hole in this metal structural part. No drilling required. I ran the wire through and then cut two lengths of split loom to cover the wire each side of the steel wall.
Here's where it gets fun. You need to remove the body panel that covers the battery. Now if you've already changed a battery you're probably intimate with this part of your car. I was not, and I have to say this was one of the biggest PITA moments of the install. There are some very simple bolts to remove in the rear part of the front wheel well, one on top and then one underneath. It was getting to the one underneath that caused me headaches. I ended up having to remove part of the actual sill so that I could bend it down enough to get some pliers in there to get to the last bolt. I think it wasn't necessary to do this in the end ( I had this panel on and off more than once during the install), but at the time seemed like one of those extra little things that you weren't anticipating.
Anyway, the idea was to locate a place to attach the fuse holder and to slide the battery part of the way out in order to reach the positive terminal.
I examined this area below, next to and above the battery and could only see one good place to mount the fuseholder. There is a bulkhead/ firewall here that I wanted to drill. I just couldn't figure out a way how I could get a drill, or any power tool, in that little space. So in the end I decided to just glue the thing to the steel, and hope for the best.
Battery area, panel removed
In the bottom right of this pic you can just make out the top of the fuse holder. I measured out my wire lengths from fuse to battery, then glued the holder to the metal (after cleaning it) with silicon adhesive. I then taped it down for good measure. I let it dry overnight, then came back and connected everything up. Once the wires were attached I used more tape to make it as waterproof as possible. The last part was soldering the gold-plated ring terminal that came with the kit to the wire, attaching the new terminal post to the battery positive, and then the wire ring terminal onto the new batter post. Push the battery back into place, check connections again, then bolt up the panel.
It's also a good time to clean out your battery area. The bottom of mine was covered with dried up deposits from a previous battery leak.
Buttoned up
One more piece of split loom protects the wire and helps keep it stealth!
HEAD UNIT INSTALL
I followed StealthLT4's advice and decided to run the HU stuff in from the side rather than underneath. I had the loom already up there. Next was the antenna lead and RCA's. My kit only came with one set of RCA leads. I wanted another set that was decent quality but not a rip-off price. I eventually found some nice Sony ones in Target that were gold-plated, and priced well.
I had more fun with my head in the storage bin running the antenna lead extension (10ft long from Installer.com) and the RCA's. I managed to get the RCA's to come out the side of the bin and stuffed under the carpet with the speaker wires, then out to the amp.
Amp with initial connections
Here's how things were looking from the back of the car.
Passenger side tunnel showing wiring routes
In this pic you can see the routing for the HU loom (multicolored), RCA's (white and green) and antenna (black). Also the rough position for the passenger side crossover. Later I discovered that I had mounted this crossover a little too low, once the seat was back in. The metal part of the seat frame will hit the crossover if the seat goes all the way back. Driver's side position was fine because, of course, I didn't remove the driver's seat!
Amp from front of car
I still had some work to do hiding wires. I was starting to get ideas about how to do this.
I was ready to fire up the amp and see if everything worked. I connected the tweeters to their respective inputs on the crossovers. The wires were too short but I just wanted to hear everything at this point. I brought out the HU and connected everything to the back with the unit sitting on the center console. I then attached the negative lead to the amp where I had left it disconnected, and then connected the battery negative terminal.
Amp powered up
Everything worked first time!
This is why I chose this HU. I wanted the red lights to match the stock lighting, while it wasn't too flashy that someone might shove a brick through my window to take it.
I found the motor antenna went up and down at the right time (when Tuner is selected), there was sound coming out of all the speakers, and I started to familiarize myself with the settings on the HU
Final part - Installing HU and door tweeters
