I'm thinking about replacing the stock radio/CD/Cassette deck on my '89 vert. Of couse, it has the headrest speakers which I think are great and plan to keep using.

Does anyone have a wiring diagram for the convetible strereo or tips on how to hook up a new deck and retain the functionality of the headrest volume controls in the center console? I'll probably keep the stock headrest speakers since they seem OK soundwise.

I've noticed an amp under the rear deck near the cheezy spare tie. Do I need to take the pre-amp output from the new deck and wire it into this amp in the back?

 

here you go, the whole S5 vert stereo wiring:
(sorry its two pictures, its just so big)

 

I tried to keep the old amp, but I couldnt get it to work right, and it would always make the system sound like garbage, sometimes popping when I hit the breaks for some reason. So I just bought an aftermarket amp and wired it so that it would turn on when I hit the headrest speaker button. I just wish there was a way that I could make the original volume controls work :/

 

Its your signal level. How much power were you running from the aftermarket radio into the stock amp. It would not handle more than about 15 watts/channel.

 

The headrest speakers in my 'vert run off the rear speaker channels from the deck. So there is where the amp gets its signal from. IT is still wired to get power, but you have to supply it with a remote signal from the head unit...search for posts by me regarding this, I confirmed wiring colors for someone in the past. I believe it is a brown/red wire that you must jumper 12vdc to in order to allow the amp to come on (I used the amp turn on wire from my deck, but you could also use any switched 12vdc lead).

 

I could not find the thread you refered to on what wire needed to be spliced in after about a half hour of searching. Would you happen to still know what wires need to be spliced in to allow the use of the headrest controls?

 

I think it's the brown/red too. This wire is behind the dash (on the big connector that plugs into the stock unit), and when it's triggered then the headrest speaker amp is turned on. Like Hypntyz also wired it to the switched on 12vdc from my new HU.

I don't remember whether the headrest speakers get their audio feed from the rear channel of the stock unit or the front, a simple swish swish of the fader will tell you (it must be rear, so the fronts are run off the stock HU onboard amp, and the rear is to the "subwoofers" and the headrest, which are independently amplified anyway. . .). So you pin match the smaller connector from the stock HU and the rear channels of you new amp. If you want to disable the "subwoofers", you can just unplug them at the speakers.

I used some plugs from Fry's for my model year, mostly so I could solder in the comfort of my living room. I believe that the aftermarket plugs didn't have connectors in place for the brown/red, so it was externally tapped. I also ran a common ground to the HU from the ground screw used by my two amps (I was running the speaker wire anyway, and ground loops suck).

You also have to get a relay and switch the reference for the power antenna. There are good writeups for that around.

So let's see, to wrap it up I've got the rear RCA's going to my sub thru the sub amp, the Front RCA's going to the front thru the front amp, the rear connector off the stock HU doing audio for the headrests, and the front connector off the stock HU doing some power stuff. I guess using the aftermarket adapter connectors is silly since only a few wires are actually used, oh well, it was $4. I have the sub on the rear channel so I can adjust it via the fader when the top is up/down. Since the headrest volume is independently controlled (still using stock amp and controls for that), this works out really well.

One member here advocates using male spade plugs to terminate the new HU harness, and then plug these into the stock connectors.

You should be able to puzzle it all out from the wiring diagram above, that's what I used.

 

Thank you very much for that I've been poking at it on and off for about two hours. I'm really not very good at this . . . :/

 

Well, I can confirm the Brown/Red wire is power. I just spliced it into Blue/White.

Then the two brown wires next to it (Brown,Brown/White) are one channel of input, while the next two wires (Blue,Blue/Orange) are another channel of input.

Pre-amped input seems to be way too little, while speaker level input is too much, so I'm going to use a little two channel 8W amp I have sitting here to boost the pre-amped signal from my head unit into the headrest amp.