2007 stereo power harness wires colour wrong

Hi, I have a Citroen C3 Cool 2007 and I'm having trouble installing an aftermarket stereo. The wires on the cars stereo power harness are different colours to all the wiring diagrams online.

Red
Yellow
Grey
Green
Green/Yellow

Could someone please help me identify what each wire is for as I am unable to get stereo to turn on/off with ignition.

Hi

The later 2007 models just have a different connector to the early 2002 models.

C3 2007 has quadlock/fakra and C3 2002 has ISO plugs


You just need to use a quadlock/fakra connector to match your new stereo, (usually ISO) and usually there is no need to adjust the wires.

If you need to identify the wires, then a quadlock/fakra diagram will show you.

Thanks. Unfortunately when I purchased the car there was no stereo and the connection block had been removed. So the connections I've made have been purely guess work

Brettels1981 wrote: ↑Thu Apr 21, 2022 8:54 am Thanks. Unfortunately when I purchased the car there was no stereo and the connection block had been removed. So the connections I've made have been purely guess work

That is a very time consuming situation to be in

I hope the car was very cheap to compensate.

There was a similar problem that you are facing here - (2003) replacement radio required. Different missing plugs because the year is different, but the same problem.





There is a Blue Haynes for the later C3 models that has some helpful diagrams for the stereo. I can't put my hands on my copy right now to confirm what exactly is included

Thanks. I'll see what I can do. Luckily it's a cheap runaround.

Had a few tries at sorting, constantly blowing the fuse on the stereo now

Use a multimeter (amazon cheap will work) to look for that computer 12v and the permanent 12v, set the meter to 20v DC range.

Earth can be found with the battery disconnected and the meter set to ohms range.

Speakers can be done with no power and a multimeter on ohms. Looking for ohms to show the speaker coil.

Green with a yellow stripe is always chassis ground (negative return).
There will be 2 wires twisted together. This is the CAN BUS connection.
1 switched power (ignition).
1 permanent power (battery positive).
8 wires for the speakers.
As Arfur says, get yourself a cheap multimeter. Use the next highest range of the meter above 12 Volts (maybe 20 or 50). Turn the ignition OFF. Make sure all your fuses (glovebox and engine bay) are OK. Check for power between all the wires and the green/yellow wire. Ignore the pair of wires that are twisted together for all of these tests. The one that has (about) 12 Volts will be your permanent (memory) power.
Turn the ignition ON. Check the rest of the wires for power (12V). Not sure but you may actually need to start the car to activate the AUX circuits. That wire with power is the IGNition wire.
Put your multimeter on low Ohms or buzzer, if it has that facility. Pick 1 of the wires that are left. Check for low resistance between that wire and any of the other wires which are left. When you get an indication of low OHMs those two wires go to a speaker. If you tap the meter probes to those wires you may hear one of the speakers crackling. That will tell you which speaker those wires go to. If you cant hear any noise, get a 9V battery and brush the speaker wires across the battery contacts. Bush or tap, the wires across the contacts, don't hold the wires to the contacts!
Repeat that for the rest of the wires.
Is the radio you are installing CAN BUS compatible? If not, ignore the twisted pair of wires. If so, test each of the twisted pair of wires to the green/yellow wire. With the ignition ON, one will be slightly above 2.5 Volts. This is known as the CAN HIGH LINE. The other (slightly below 2.5V) is know as the CAN LOW LINE.
If you are really hard up you can use a 12V 5 watt light bulb to test for power. Use the 9V battery to test the speaker wires. Test for power with the light bulb first, don't apply the 9V battery to the power or ground wires!
Good luck.