Stereo Installation Help [86/944]

[exitwound]

Well, I'm attempting to dissect the remains of what the previous owner had done to install a stereo. I bought the car with a disc changer in it, but no head unit. Factory speakers are gone as well, replaced with Kenwood and Generics. Oh this is fun. I've looked through the wiring diagrams, but I can't seem to translate the flat pics to actual three-dimensional space.

After removing the remains of his changer, there are three bundles of cables exposed. I need to identify what these bundles might be for.

Bundle 1



I've managed to deduce that these are the speaker leads. I've labelled two of them (hard to read in the pic) front right and front left as they match the wiring attaching to the front speakers behind the grills. Looks like:

• Left Front: Brown and White
• Right Front: Black and Brown/Black

I'm left with "Red & Red/white" and "Yellow & Yellow". It looks like the previous owner at least used color coded his extension wiring to match each speaker. Which do you think is which?

Bundle 2

• Three wires, two of them very large.
• One is Red/white, the second full brown
• The third orange/white.

Each has his own proprietary connector meant to go somewhere special. I have no idea where though.

Bundle 3



Lots of wires in this bundle. There's (from top to bottom in picture):

• Red/white
• Two green wires that have been spliced into one by the previous owner
• Two larger brown wires spliced into one.
• Three red/black wires
• A Twisted pair with a proprietary connector.

What's missing in the pictures: A light, just like the one that goes behind the clock. The antenna hookup is there as well.

Questions & Thoughts
I know the car used a rear/front fader on the console. I don't want to use this and don't really care if it's non-functional when connected to my headunit. The PO cut those wires behind the switch. I do not know if any of those wires are part of this bundle though.

I wish to replace the speakers eventually, not right now. I read thru Clark's procedure for replacement and I can't believe the rear quarter panel windows are part of the deal! I can't remove the big hex pins that hold the rear seats in place upright though with a normal philipshead screwdriver. They're too large. Do I need a special tool for this?

I wish to set up the stereo this way. Headunit will power all four speakers. An amp will be connected on remote lead to power a "small" bass cannon. What is the best way to wire this all up? Should I do it myself or take it somewhere? I would never take it to a Best Buy or Circuit City, but a local stereo installation shop that I've shopped before. They do nothing but car stereos, a little family owned business. Do you think I should trust the car with a shop such as that? Think they'd know enough to wire up the car and not end up breaking my quarter panel windows for instance?

Which wires in the above bundles are not going to be used when hooking up a stereo in this fashion?

Thanks!

[Wipeout]

The shop that took care of my speakers (like yours, family place that only does car audio) was able to do the rear speakers without removing the glass. You have to be careful and not expect the panel to come all the way out.

I can't ID the wiring for you, looks like a hack job. Kudos to you for cleaning it up, though!

[jcommin]

Clark's garage has a good article on stereos for your car. I replaced my speakers on the doors and rear panels. There may or may not be any differences from my 83 to your 86 but I thought the fader was gone when the dash was changed in 85 1/2. My 83 is designed to be a two channnel system. The left front and rear speakers are ganged together. Same for the right. Everything goes thru the fader.

To get the most out of a new system you should seperate each speaker to each channel and eliminate the car fader. The stereo should have controls to adjust each speaker left/right, front/ center.

I was going to do that but that's a job because the each speaker side is ganged together. I did want to go thru all the trouble of rewiring. I am only using 2 of the channels on my system. I still use my fader. I decided to keep the same wiring because: I didn't have the pateince to do it and the car is small any stereo is more than adaquate for me even using only 2 channels.

Now since you are rewiring everything, you have the chance to make it like you want to.

Taking the rear speakers out is a job. You can do it without taking the rear windows out but it calls for allot of patience getting the interior vinyl away from the rubber window molding. I took mine out with the windows removed. The rear windows need to be 'roped' in. I had a window guy do that.

Good luck

[88BlueTSiQuest]

On the top picture, the wires that are crimped to the factory harness should be the same color as the speaker wire outputs of your new stereo. Simply match them up.

White & White/Black = Left front + and -
Grey & Grey/Black = Right Front + and -
Green & Green/Black = Left Rear + and -
Purple & Purple/Black = Right Rear + and -


The other three wires with crimped on connectors would also correspond with your new stereo. 3rd picture.
Porsche Red/White would go to your new stereo's Yellow(battery) wire.
Porsche Lt. Green/Yel(?) goes to the new stereo's Red(ACC) wire.
Porsche Brown goes to the new stereo's Black(ground) wire.

The bundle in the 2nd picture I can't identify. Colors should still identify them as Ground and Battery +, not sure on the Red/Yellow wire though.

[exitwound]

Awesome. Thanks for all the detailed info!

I'll post back when I start the actual installation.

[88BlueTSiQuest]

Originally Posted by exitwound

Awesome. Thanks for all the detailed info!

I'll post back when I start the actual installation.

Don't forget to tape off and insulate any un-used wires when you are done. Some of those cut wires could be for the factory light illumination. If those hit ground you could blow the dash light fuse, or worse, fry the dimmer knob. I usually use crimp caps to cap unused wires, but you could merely tape each wire off individually, then tape them together to keep it all clean.

If you want to verify the speaker wires, you can do so with a AA or AAA battery. Simply strip the leads, and put one lead on top of the battery, the other on the bottom, just touch a lead to the battery and you'll hear it pop.


I haven't pulled the rear seat pins, and I'm guessing mine are different than yours as the pin appears to be screwed in through the panel, this leads me to my next question that might answer the riddle of pic number 2...

Is this maybe an 85.5 car? My guess on pic 2 is that it's maybe the remnants of the cigarette lighter wiring(early cars had the lighter above the radio. Given the gauge of wiring, you'd have power, ground and light and those plugs look to be the type that would be used.

It being an 85.5 would likely also explain why you have phillips head screws holding on the seat catches(my '83 has a pair of screws holding that plate on). My '86 doesn't have a plate at all, it's just threaded through the panel straight to the car itself. Either way, just use a ¼" socket with a large Phillips bit(#3) and a ratchet, it should give you the leverage needed to break those screws loose(probably locktited in).

The window is pretty easy to pull, just read the Clarks write up, it sounds worse than it is.

[onZedge]

Bundle #2 is the harness for the factory Equalizer/Booster amplifier:

Big red/white is ignition switched power for the booster amp
Big brown is ground for the booster amp
Little red/white (no orange/white on schematic) is for antenna amplifier switched power and head unit switched power from the booster amp

[88BlueTSiQuest]

Originally Posted by onZedge

Bundle #2 is the harness for the factory Equalizer/Booster amplifier:

Big red/white is ignition switched power for the booster amp
Big brown is ground for the booster amp
Little red/white (no orange/white on schematic) is for antenna amplifier switched power and head unit switched power from the booster amp

I thought that, but didn't reply it as I wasn't sure that option was available for MY 86.

[HondaDustR]

Depending on what kind of system you're installing, you might want to route a new positive wire. A more powerful head unit might draw more than what the original harness can handle, and even if it doesn't overload it, the extra resistance of inferior wiring will diminish performance.

The PO hacked up a stereo instalation, which I had to fix when I got my car. It was a 250W head unit, and he reported it was blowing fuses, so I just got a inline fuse holder and some 10 guage wire from Lowes and ran a line straight to the battery. It works great. The only thing is I didn't bother with rigging it up to the accessory wire on the original harness, so I have to manually turn it off, but I don't care.

[exitwound]

As far as I know, the car is an 86 n/a. It definitely is not an early model or an 87. So either it's an 86 with 85.5 parts, or an 85.5 masked as an 86.

My rear seat pins are large philips heads, not as big as the giant mole that sits in the middle half way up, but larger than all the others that hold in the side panel. A normal #2 philips doesn't fit. However, I did not try a #3 yet. There are two of them screwed thru a plate that goes through the side panel.

So...the headunit I'm putting in is an older model Clarion (DB315 ProAudio). I am not an audiophile and this headunit has worked for me for years). In the VW, I had a battery cable run directly and not through the wiring of the car from the original stereo (or should I call it a mono? hehe).

The cigarette lighter in my car works perfect as is. Therefore, the wiring in the pictures above do not belong to the lighter. I plan on removing the lighter anyway as no smokers will ever touch my car. ever. period. The cigarette lighter is a switched 12v circuit correct? Could I tap into that to power the headunit when the key is turned? Should I instead go to the fusebox somewhere?

[onZedge]

Originally Posted by HondaDustR

...so I just got a inline fuse holder and some 10 guage wire from Lowes and ran a line straight to the battery...

The '80s era radios used a big ground wire and a big switched ignition wire. The clock memory wire (constant power) was a weeny little thing. In modern in-dash units, the yellow constant power wire is where the internal amplifiers get their power from while the switched ignition wire has very little load.

When I upgraded my stereo, I added a whole new fusebox just for the head units internal amp, equalizer and high pass amplifier. The rear low pass amp gets its own circuit breaker and dedicated (from the battery) power cables. I need to either upgrade the cable size or add capacitors as my headlights dim (at very high listening levels) with the bass drum notes - ever so slightly, but noticeable if you are looking for it. The 90 Amp factory alternator can't keep up with the peak power demand.

I'll add the link to where I posted the details later...edit: here it is. We're getting there!

[88BlueTSiQuest]

Originally Posted by exitwound

As far as I know, the car is an 86 n/a. It definitely is not an early model or an 87. So either it's an 86 with 85.5 parts, or an 85.5 masked as an 86.

85.5 was the mid-year change from the old style 944 to the new style. So an 85.5 has everything the 86 has, you'd have to look at the build date to determine.

I'm still thrown by the screws holding the seat pivots on.

Here's my '83.



This is the '86 951.




Enough on that. The lighter is constant power, always hot.

As to the radio wiring, the factory wiring is adequate for that older radio. Alot of the new radio hype as to power wire is just that, hype. Go look at the size of a good 200 watt 4 channel amp, then look at that AM/FM/CD player, and tell me how they crammed that 4 channel 200 watt amp inside that DIN sized chassis. Start reading the small print, and you start noticing that that 45x4 Pioneer Mosfet deck is only put out a clean 12wRMS of power. Any of the others that also claim massive numbers are also blowing it out of proportion.


< ---- Ex- MECP 1st Class car audio installer, over 12 years experience.

[onZedge]

Originally Posted by 88BlueTSiQuest

...As to the radio wiring, the factory wiring is adequate for that older radio. Alot of the new radio hype as to power wire is just that, hype. Go look at the size of a good 200 watt 4 channel amp, then look at that AM/FM/CD player, and tell me how they crammed that 4 channel 200 watt amp inside that DIN sized chassis. Start reading the small print, and you start noticing that that 45x4 Pioneer Mosfet deck is only put out a clean 12wRMS of power. Any of the others that also claim massive numbers are also blowing it out of proportion.


< ---- Ex- MECP 1st Class car audio installer, over 12 years experience.

So what are you saying here? That the factory 0.5 sq mm constant power wire is sufficient for a new deck with 4X12WRMS? I don't think so. The OEM factory configuration used a 2.5 sq mm switched wire for the OEM 2X10WRMS (if that much because there was no CEA in the'80s) deck for a reason.

< ----Current I&C and Electronics Engineer, over 26 years experience.

[exitwound]

Originally Posted by 88BlueTSiQuest

Here's my '83.

My 86 has these connections, not the one from the other picture. Those are the screws I can't get out.

[88BlueTSiQuest]

Originally Posted by onZedge

So what are you saying here? That the factory 0.5 sq mm constant power wire is sufficient for a new deck with 4X12WRMS? I don't think so. The OEM factory configuration used a 2.5 sq mm switched wire for the OEM 2X10WRMS (if that much because there was no CEA in the'80s) deck for a reason.

< ----Current I&C and Electronics Engineer, over 26 years experience.

Considering that we are talking about ~7.5amps of continuous draw given 50% amp efficiency at 48wRMS, at full tilt. There is what, a pair of 18g wires that feed constant to the deck.


Now back to said 200watt Pioneer, I happen to have a Premier model DEH-P750MP sitting here. Pioneer was so sure about the power potential of their 50w x 4 MOSFET design, that they equipped it with a 10 amp fuse to protect it's amplifier section. Fuse 36 is protected by a 7.5amp blade, and I haven't blown it yet.

[HondaDustR]

About the 200W deck, it will draw around 12W per channel average with normal volume. It can hit 200W peak power, especially turned up with lots of bass, but it is only in spikes. It will not draw 200W continuously with normal music.

The point, though, is when it does need to hit those big beats, will it have enough wire to feed it instantaneous juice. It's not about if the wire can safely supply the amp, but if it can supply it with larger currents easily when it needs them without voltage drops (which hurt performance). It's why good subwoofer installations use something like 4 guage wire, unless you're running a small amp. There's no way any realistic sub system is going to overload a 4 guage wire, but those surges of power (for some amps, up to 1000W for a split second) need to be well supplied (especially with longer lengths of wire...larger wires have less internal resistance per foot), or the amp will bottom out from the voltage drops. It's also why they use huge capacitors right next to very large amps so that it always gets the current it needs to produce nice crisp bass.

Granted, a 200W head unit driving 4x6" speakers is not going to be nearly such a big deal, but if you're talking 20 year old 16 guage wire plus a 20 year old radio relay, it might be worth running a better voltage supply if you want the best possible performance. But if your head unit is nothing special, you don't play your music loud, and you don't care whether it sounds as good as it possibly can, then the factory wiring should work safely.

[onZedge]

A 0,5 sq mm wire is equivalent to a 20 AWG wire. 7.5 Amps is very close to the maximum wire rating. A 20 AWG wire is rated at 0.18 ohms per foot. At 7.5 Amps current draw you lose 1.35V through a one foot long piece of 20 AWG wire.

In mobile audio amplifiers, voltage is everything since you only have 12 to start with (OK, whatever your voltage regulator rating is).

[HondaDustR]

You also might want to double check that the stripes all go to either the + or the - on each speaker, or the sound will suck. Who knows, after what the PO has screwed up already.

[Dave L]

how difficult would it be just to run all new wire? power, speaker wire the whole deal? I know when I did 2 different e30s thats what I did to avoid the small amp, fader switch and other misc gagetry that was state of the art back in the 80's.

[88BlueTSiQuest]

Originally Posted by HondaDustR

About the 200W deck, it will draw around 12W per channel average with normal volume. It can hit 200W peak power, especially turned up with lots of bass, but it is only in spikes. It will not draw 200W continuously with normal music.

You aren't going to get a 200 watt peak out of a deck that only runs a 10amp fuse for it's amp protection. If that amp section is only 50% efficient, and running on 13.6v DC, 136watts is putting 20 amps load on that 10amp fuse. Most blade fuses will blow at about double their rating.

That's the whole issue there. CEA has control over what amp manufacturers claim for power output, but for Head Unit output, they are still a little relaxed. It looks like more of the big manufacturers are putting forth an effort in providing the RMS output, but the peak output numbers are still blown out of proportion.

Who really cars if a deck can do 50x4 at 10% THD with bass, treble, and loudness up to full. Then you start digging even deeper, and you find things like the RMS power testing was with a limited bandwidth such as 22wRMS x 4 from 50-15kHZ.

Base your wire upgrade on the manufacturer's fuse size, as they put that fuse in to protect the amplifier section.