lilredpo

I have an Alpine CDA-7838 that is currently only using the front door speakers.

It was part of a system installed by the PO. I say was, because the PO pulled what components were there when I bought the car.

It hasn't been a problem because I rarely use the radio. But I would like to figure out what's missing as opposed to taking it to a shop. It's probably plug and play to at least get the rear speakers working with decent sound.

On the left side of the car is a standard speaker wire that runs to the rear speaker inside the panel. I do not know what kind of speakers are installed but I assume they support the previous system. I used a 9v battery to check both spreaker wires ran to the rear speakers.

Also on the left is a "monster Cable" and a Blue cable.

On the right side are 3 sets. A rear speaker wire, a big red cable and a white cable that contains 4 smaller wires.

I have not looked behind the head unit or have any wiring diagrams. I also looked on Alpine.com with no luck.

Any help would be greatly appreciated. I can do the basic electrical work, but I am from the old school of car audio, before amps, pre-amps, sub woofers, etc.

Attached is a picture of what was under the rear carpet.

Thanks in advance
Ray

pikey7

Looks like he had a 4 channel amplifier wired in there aswell. Just extend the rear speaker wires to the radio. (unless you want to add an amp, in which case....... have fun!)

PennyWise

I'm gonna guess here.....
Speaker wire speaks for themselves.... these where connected to the output of the AMP. If you do not want to use an amp, these can be connected directly to your head unit's speaker outs.

Blue wire: This is the remote power on/off switch. The other end in connected to your head unit and when you switch it on, a light current is sent to the amp to switch it on via a relay.

Big Red wire: power source of AMP. Always connected to the battery.. hopefully fused.

Ground connecter : missing!... AMP was ground to the chassis somehow.

Monster Cable : These are the liine-out's from the head unit, but as there is only 1 set of out in the radio, he has a splitter here to a 4 channel amp

Small white wires : He could have had a cross-over here and these came from the cross-over to possible Ball tweeters in the front of the car near the front pillars.


so.. to make it all work... get an AMP and match up the wires... or , leave the AMP and just connect the speaker wires to back of the your radio's speaker out connectors.

Also... tape up the Redwire just in case its still live.....

I'd leave the other there for future... just in case


Happy tunes....

88BlueTSiQuest

If you aren't going to install an amp back there, what You'd need to do is either run new speakers wires from the rear speakers(you can splice into those existing rear wires to keep from taking the rear of the car apart) up to the front, or pull the car apart and attach the rear speakers back to the factory wiring.

Behind the deck.. The Purple wires are the right rear outputs off the Alpine deck(black stripe signifies ground). The Green wires are the left rear outputs. Just to verify he's got it hooked up correctly, grey's are right front, and whites are left front.

When behind the deck, be sure to disconnect the blue that's ran to the back, and be sure to insulated the blue/white wire that the blue wire was attached to. If this wire goes to ground, worse case scenario, it can fry the deck(sometimes it'll just fry that output though, leaving the rest of the deck functional). I'd also unplug the RCA's, as sometimes when those touch ground they can cause engine noise through your speakers.

88BlueTSiQuest

He either hasn't found it yet, or it was pulled out with the amp, as most ground wires are only about 3' long anyways. I've done that myself, pull the ground wire instead of leaving it in the car.

The white multi-con wire is still a mystery, it could very well of fed some x-overs for some front speakers.

phil0618

I'd be very tempted to just buy a small amp and mount it where the PO clearly had one. Amps can be had pretty cheap - less than $100 depending on what you want and will no likely sound better even if you don't play it very loud simply because you'll get better dynamic range and less distortion.

Generally the hardest part about the external amp is running the wiring and since the PO has done this for you I'd take advantage of it.

It's also possible that the PO did have a 4 channel amp and it powered a sub or based on the LF/RF labeling maybe it was a 4 channel amp that powered both front and rear speakers. That is a distinct possibility and when he removed the amp he just took the speakers that used to run to the rear amp and connected them straight to the Alpine.

In any event the harder part of car installations is running all the wires. Since the PO already did that I would just buy a small two channel amp and place it in the rear using all of the wiring that is already in place. You could go to Craigslist or Ebay etc if you are so inclined.

Good Luck,

michaelathome

The AMP was likely grounded right in front of the driver side tail lamp under the carpet, that's where all of the rear lighting is grounded, take a look.

Factory wires are brown, everything that is in the pictures was added by PO.

Blue wire is the remote switched power, when you turn on the head unit it turns on other "switched" items such as an amp or a cd changer.

Red shoud go straight to battery.

As pennywise said "Small white wires : "He could have had a cross-over here"

What I am thinking and this is only a guess is that he was running pre-amp out to the rear with a 4 channel amp. He was probubly allowing the head unit to power the front speakers and using the amp to power the rears and the remaining 2 wires could be bridged to a higher output single channel sub in the hatch Kinda what like I am doing. Kinda. The sub would have required caps/cones to eliminate the highs and mids and that could explain the smaller wires. to be sure you really need to figure out where those go to.

Michael

lilredpo

Thanks everyone.

Well, I just poked around some more.

The thick red goes through the firewall to the battery, but is cut.

The thick White w/red stripe is same gauge as red. Has 4 smaller wires, Red, Blue, Black with blue tracer and Black w/lt purple tracer.

No sign of a ground in the back, but that's an easy add.

I looked behind the head unit without removing and saw the white/red spliced to wires going to the unit.

I guess the next step is to remove the console to get to the back of the unit and see what's going on.

lilredpo

Another question...could I place a small amp there under the carpet? Would it get too hot or need to be fastened down?

Thanks again.

Ray

Techno Duck

I wouldnt mount an amp underneath the carpet. The best position is usually in the spare tire well.

phil0618

Hi,

I agree that in the spare tire well or the little cubbies behind the rear wheel would be better for the amp. All amps produce some heat and are better off if they can breath. There is a class of amplifiers called 'Class T" amps that run VERY efficiently and sound good too. Blaupunkt made some and while discontinued they can be found on Ebay.

Bottom line - don't place the carpet on top of the amp give it at least an inch or two on the top and sides. also try to mount it firmly in place - don't let it bounce around.

Good luck,

Phil