87 scirocco dash lights cock up...

[87rocconewb]

Hi everyone,

First time poster, I hope this is in the right spot. I just recently acquired a mk2 Scirocco (1987, 8v), and due to an idiotic radio install am now having an electrical issue.

The seller hooked up a new head-unit for me, and unfortunately hooked the dimmer control line (grey/blue) in with the ground (I have no idea why).

Everything seemed fine until the first time I drove the car at dusk, and turned on the headlights/dash lights. At which point smoke started coming out of the dash, behind the headlight control switch. I turned off the radio and lights and limped home, but now the interior instrument lighting is no longer working (I tested it when I bought the car, and it worked then). I pulled the headlight switch/dimmer control, and it has completely melted the grey/blue lead (marked 58b on the back of the dimmer control, at the top of the switch). The grey blue wire for dimming at the radio (same wire, I presume) is also melted. The problem is, I do not know where it runs in between. I pulled the panel under the dash, and it appears to run straight from the switch over to the radio (this is just a brief glance, tracing it by finger, without pulling the loom apart), but that does not make sense, if it also controls dash lighting.

Any advice on where to start with this? Or knowledge of how this wire runs? I am very angry at myself for allowing this to happen, as the car is otherwise in fantastic shape! And I would like to be able to drive it at night...

Thanks,

Will

[DJPremier]

For reference. All the stuff I pulled out of forum posts about head unit wiring. Good luck with it.
VW Rocco Stereo Wiring
Firstly the grey and blue cable in the car's loom is for illumination, modern stereos have their own lighting, so tape the end up and tuck out the way.
Connect the red and yellow cables together with the red on the car's loom, this will give perm live and will save your preset stations.
Sciroccos didn't leave the factory with a switched live, they had perm live only.
For ease you can take a switched live from the heater switch above the radio.
For the electric aerial you should have a blue cable which is the switch, this needs to be connected to the blue cable off the stereo. The red cable off the aeriel needs to be to a perm live, and lastly the black cable on the aerial is an earth.
The speaker cables are generally green and green/black, purple and purple/black, white and white/black and grey and grey/black.
What I do is get the stereo working and the aerial lead fitted, then set the fader and balance control to one side front or rear and then try the cables on the loom until the correct speaker is working,then do that until they all correspond to the correct setting. Not too difficult but worth spending some time on doing a good solid job.
1981-85 Volkswagen Scirocco Wiring
Constant 12V+ Red
Switched 12V+ n/a
Ground Brown
Illumination Blue/Gray
Dimmer Blue
Antenna Left Front
Front Speakers 4" x 6" Doors
Left Front (+) White/Black
Left Front (-) Brown/White9
Right Front (+) Green/Black
Right Front (-) Brown
Rear Speakers 4" x 6" Side Panels
Left Rear (+) White/Black
Left Rear (-) Brown/Black
Right Rear (+) Green/Black
Right Rear (-) Brown
Typical Head Unit Wire Harness
Function Typical Wire Colors
Memory / Constant 12V(+) Yellow
Switch / Accessory Red
Ground Black
Illumination Orange/White
Antenna Remote Blue
Amp Remote Blue/White
Left Front (+) White
Left Front (-) White/Black
Right Front (+) Grey
Right Front (-) Grey/Black
Left Rear (+) Greesn
Left Rear (-) Green/Black
Right Rear (+) Violet
Right Rear (-) Violet/Black

[87rocconewb]

Thanks. I actually got the radio hookup fixed, the problem is now that incorrectly wired blue/grey illumination wire is melted, right up to the back of the headlight dimmer switch (where it's labelled 58b on the back of the headlight switch). I need to know where that wire runs in order to replace it/check surrounding wires for damage...

[ianaudia4]

The illumination cable (blue/grey) also goes to the ashtray light, fag lighter light and the heater panel illumination. I would be cautious using the headlight switch!

[87rocconewb]

Why? Because of possible damage to adjacent wires? I cut 58b off and taped it (the wire will obviously need to be replaced anyway), and I disconnected the other end I could see from the radio...

Will this cable not also go into the instrument cluster somewhere? Or is that another lead off of the headlight switch? Anyone have a wiring diagram? I will be getting the Haynes manual, but I live in the sticks (in rural Canada), and it will be a few days until I can get to the city... which is a 2 hour trip, one way.

[marcus]

The Haynes manual is out of print, so make sure you know where you can get one before you make the journey. You might have to get it online.

[87rocconewb]

Thanks for the heads up... internet inventory says one is available, but knowing that they're out of print, I will call ahead to make sure...