Replacing 'multiplex' head-unit

mvoong · Post by **mvoong** » Wed Apr 17, 2002 3:52 pm

To all those who've replaced their head-unit for the 2002 multiplex wiring loom. How did you overcome the permanant power on when changing head units? At the moment, after replacing the head unit with a Sony one there is a permanent power supply to the head-unit even when the key's not in the ignition.

Also does anyone know where the wires are for the display and stalk control? From the back of the stereo there are only 2 ISO plugs (1 for speakers and 1 for power) which slot in the back. There are no other wires which slot into the stereo so I can't trace where the controls for the display and stalk are.

I know this is not a problem for the pre-multiplex system and I'm questioning why Peugeot bothered with this system,after all the signs are they're replacing the multiplex system very soon as well!! Many thanks

Michael

rob · Post by **rob** » Wed Apr 17, 2002 8:44 pm

The stalk and display wires are in one of the ISO plugs.

As for the power staying on, you just have to let it turn itself off after 30 minutes when the car audio wires go into power save mode.

mvoong · Post by **mvoong** » Thu Apr 18, 2002 11:59 am

There must be a better way than waiting half an hour!

??:

mvoong · Post by **mvoong** » Wed May 01, 2002 11:50 am

After speaking to the Master Tech at my local Pug dealer (Peter from Belmont Edinburgh), I've finally managed to come up with a solution to the permanent power feed to my stereo. Of course all this problem arises from the stupid multiplex system Peugeot installed to the 2002 model. By taking a feed from the Brake Cable Wire (situated underneath the glovebox) and using this as the auxiliary power signal for the Headunit it will ensure the headunit only comes on with the ignition switch. The only downside to this solution is that it does not work it the first ignition position (a small price to pay). For those of you who wish to do this the instructions are as follows:

1. Locate Brake Cable under the glovebox-you will see a wire plugged-in right underneath the glovebox.
2. Pull out this wire from the connector (making sure the ignition is off to prevent potential shorting) and then pull out wire from plastic housing (you'll need a sharp pointed instrument to undo the little catch to release the cables).
3. Next take an appropriate size power cable and attach onto the left-hand of the two cables (I think it's white in colour but it's definitely on the left, if in doubt use a current meter which is readily available at DIY and car places-remember there is no current flowing until you switch on the ignition) then reconnect everything as you found it.
4. From this wire attach an appropriate size fuse connector and then this can be connected to the back of the stereo.
5. In the back of the stereo there should be two power feeds to it. One permanent feed for the memory such as radio stations, clock etc... while the other works through the ignition switch. This is the one which should be replaced with the cable from the brake cable. If you don't know which is which just use trial and error. If it's wrong then whenever you switch off your ignition then the memory will be erased so it's just a case of swapping the wires round.
6. Admire lovely new stereo!!!

As I've said, I have now done this to my own car and it seems to work fine-even the brake lights still work! The only minor downside to this solution is the stereo doesn't work with the first ignition position so if you keep the stereo on in the second ignition position it eventually switches itself off (30 minutes) due to the economy mode function. All-in-all I'm pretty happy with this setup. If anyone has any problems with my instructions just get in touch. Now all just have to do is get round to fitting my two amps!!!

Michael

Derek · Post by **Derek** » Wed May 01, 2002 3:45 pm

nice to see the monkeys at belmont have eventually learned how to do something right

mvoong · Post by **mvoong** » Thu May 02, 2002 11:41 am

It took him several goes and several days to find an appropriate wire for me to 'tap' into. Initially he insisted the power cable from the back was connected to the ignition switch and I obviously just don't know how to connect a stereo!! When I eventually convinced him this was not the case he was quite helpful, although all the wiring diagrams that he has are not of the multiplex system. This meant he had to play around to try and find something for me and thankfully he did...Cheers to him

gsp · Post by **gsp** » Fri Jun 07, 2002 8:22 am

Hello guys i had the same problem yesterday when i tried to put my sony in. There is a wire on iso connector which has power on the 2nd position of the switch so itsn't needed to search for brakes wire.I didn't know that the accessories power wire goes off after 30 min. is it really like this? Also has anyone any information of the cables for display and stalk? (pins,data,clock etc?) I can provide ANY information on sony car audio..
thanks

mvoong · Post by **mvoong** » Fri Jun 07, 2002 12:54 pm

The wire in the ISO which is supposed to be on only with the ignition switch only works with the original head-unit. This is not the case when you fit an after market headunit like the Sony one that you installed. As an electrical engineer you should be able to check the power of this cable and find that it is on even when the key is not in the ignition. That is why your head-unit is on even when you remove the key. The new model cars have an auto powersave function which switches it off after 30 minutes. This however will still eventually drain your battery this is why I took the wire from the brake switch cable. hope that helps.

Michael

gsp · Post by **gsp** » Sat Jun 08, 2002 2:59 pm

thanks.. it realy shuts off after 30 minutes.. so its ok..Now i have the second problem!! I want to pass inside the power cable for amplifier and the wires of alarm system, any good and easy way?

fanmail · Post by **fanmail** » Mon Jun 10, 2002 1:02 am

Hi,

Some added info for the 2002 model.
The cables to the glovecompartment light are coupled to your ignition switch. So far the best one to get your power. Just remove the headunit and look inside up to the fans. You'll see the cable running. Easiest method to get your juice from this one.

BTW this one works in the first position to!

<font size=-1>[ This Message was edited by: fanmail on 2002-06-10 00:04 ]</font>

mvoong · Post by **mvoong** » Mon Jun 10, 2002 11:39 am

Thanks Fanmail,

I'll have a look at it the next time I'm free and try and sort it out. Cheers

Alex LS · Post by **Alex LS** » Mon Jun 10, 2002 2:36 pm

Fantastic! I can start planning to buy my MP3 headunit now

Alex LS · Post by **Alex LS** » Mon Jun 10, 2002 10:50 pm

Actually, what's the rating of the wire to this light? Will it be able to power a headunit adequately?

mvoong · Post by **mvoong** » Mon Jun 10, 2002 11:04 pm

This power lead basically sends a signal to the headunit to turn it on...there is another power lead which powers the headunit.

gsp · Post by **gsp** » Tue Jun 11, 2002 10:29 am

Finally i connected my sony just fine! In my model i don't know why.. it turns off after about 3 or 4 minutes, (when the display on the board goes off). An powers on when you just unlock the car! So when you get inside the music welcomes you!! Thats great finally!