Hi.
I've just fitted a stereo unit to my 940 as it didn't have one and the wires were butchered.
I followed this guide and the stereo works but I have now got no headlights.
Any ideas?

 

I have the following wires left over.
Green
Yellow
Black
White
White with yellow stripe

 

on my 92 740/940 wiring diagram, a green wire at the amplifier connector (over by the steering column) pin 13 is the right rear door speaker '-'.

a white wire on the amp connector pin 6 is the front left door -
there's also a white wire at the main stereo connector pin 7, which is the dashboard light rheostat dimmer, and should be left unconnected and taped up.
a black wire on stereo connector pin 8 is that same rheostat, tape it off.
another black wire on stereo connector pin 10 is ground
a yellow-white wire on stereo connector pin 6 is dashboard lighting, leave unconnected and taped off

i don't show any solid yellow wires. yellow-brown and yellow-grey go to the left rear door speaker.


this is how I wired my 92... note I used component speakers and mounted the tweeter in the dash and the woofer in the front doors, so I've got external crossovers in here.
https://docs.google.com/document/d/1...acaAn6M1zjB8io

 

Your headlights don't work because you did the wiring with the battery connected.
Am I right here?
You most likely blew the fuse. Check it.

 

heh, 'the' fuse? each headlight high and low beam is on a separate fuse.


oh. looking at the 1992 740/940 wiring diagrams, that yellow-white wire to radio in 6? it also goes to the main headlight relay, so if there's TWO yellow-white wires, they have to be connected together.

I've *ALWAYS* gotten the aftermarket stereo adapters that plug into the factory harness so I don't have to butcher any wires. I hate it when I get a used car and someone has chopped wires here and there to hack stuff in.

 

I'm used to having one for low, one for high. Sorry. Lol. He didn't specify whether or not the highs worked.
Also, WHY ARE THE HEADLIGHTS WIRED IN WITH THE RADIO?!?!

 

the yellow/white wire goes to the factory radio to turn on its night time lighting, it also goes to the headlight relay coil to power the headlight circuits, and it goes to the rest of the dashboard lighting.

 

Ah, that actually makes perfect sense.
I still think there should be something between them so as not to kill an important function with the radio.

 

well, OP said someone butchered the wiring. not much gonna protect against that short of putting all the wiring behind armored conduits.

 

All sorted now guys, thanks.
It was the yellow/white wire that was the problem.
I didn't use a harness as the plug had been cut off the wires si I used connectors to join the wires from the rear of the stereo to the existing wire.
Don't worry it's all safe and done properly.
The only issue I'm having now is when I brake the passenger light goes out at the rear instead of getting brighter.
The drivers side works fine.
I replaced the bulb as it was blown so wondered if it was anything to do with that. Also the bulb warning light is constantly illuminated on the dash.