Power supply issue

[Valandil]

I've got a strange electrical problem in my 02 HDI coupe. It seems like the drivers side of the car isn't getting power when the ignition is off. Like the seat moves forward when the backrest opened as normal when the ignition is on, but not when it's off like the passengers side does. And the central locking works when the ignition is on, but not when it's off (rendering it rather useless!)

Any ideas? I can't think why the ignition being on makes a difference to these systems!

[Parm]

Have you put it on diagnostics?

[Valandil]

Yes, nothing that could be related except possibly an airbag supply voltage fault, which I suppose could be related if they use the same power cables.

[Valandil]

Now I think of it the headlights don't come on when the ignition is off either, that's not normal I take it? Maybe the bsi isn't getting power, though like I said the passengers seat works fine, is that on a separate circuit to the drivers seat? Does it not go through the seat ecu?

[steve_earwig]

It's on a separate circuit. The seat ecu has four feeds from 3 fuses, all separate from the passenger seat. I've been trying to follow your symptoms through the wiring diagrams, however everything but the seat ecu heads back straight for the BSI

I suppose it might be worth checking the fuses (8, 16 & 22, passenger fuse panel) but I suspect it's not going to help.

Anything else not work?

[Valandil]

It's difficult to know what isn't working as this is the first 406/coupe I've owned! The electric windows don't work when the ignition is off but that might be normal.

The other day I tried to add a new key to the car with pp2000. There's a bit where it wants you to turn off the ignition, so I did, and then it lost connection to the bsi. I thought I was doing something wrong as I thought pp2000 had no connection to the bsi whatsoever when the ignition is turned off (so I was wondering why it wanted me to turn it off), but now I'm wondering whether that is incorrect. Should it be able to communnicate with the bsi in this instance or did I follow the instructions wrong? If it should be able to connect to the bsi like this with the ignition off, then that would seem to confirm my thought that the bsi isn't getting power when the ignition is turned off.

I did check the fuses when I got the car but I'll have another more thorough check either tomorrow or friday when I see the car again (I work away mon-thurs).

As I understand it the bsi has two power inputs, one that goes through the ignition and one that goes through F9 in the fusebox underneath the bonnet and then straight to the bsi, is that correct? Does anyone know which pin on the bsi connector the positive cable straight from the battery is? The only thing I can think of is a problem in this circuit. I assume the bsi only has one earth?

Thanks for your help, much appreciated!

Edit: The windows do drop slightly when the door is opened (as they should on the coupe) with the iginition off though. Don't know if this has to go through the bsi to work though

[steve_earwig]

Try MF6 (big fuses, engine fuse panel).

Not that it has much to do with the BSI that I can see but it does supply the permanent feed to the seat ecu and the diagnostic connector The fuse diagram also says one-touch windows and, er, passenger's electric seat

I'm not really sure where the switched live is to the BSI but the permanent ones are MF4, MF5 & MF7. Interesting.

[Valandil]

I'll have a look and let you know, thanks!

[Valandil]

I didn't know about the fuses underneath the ones under the bonnet! They're all fine though, unfortunately.

Looking at the fuse box under the steering wheel though, I'm not sure if the fuses are right! It certainly doesn't match the handbook. If you hold the handbook so that the position of the bsi fuses match then the fusebox appears to be upside down! And either way up the fuses don't actually match. So I don't know what to do, I can't match up the fuses as they are because the number of slots in each row relative to the shunt positions (none of which are used in my fusebox which I think is wrong) don't match up. I could put them in as if the fusebox was the other way up (so that the slots do match up) but I would be surprised if the fusebox actually was upside down.

I hope that made sense, I've attached pictures to try and illustrate my point. I don't know whether to trust the handbook though, my old man said that in his experience they're always wrong.

What I really need is a picture of someone else's coupe to compare! I'll ask on the coupe forums I think.

[steve_earwig]

That's the diagram I have, which seems to work for my estate (on everything I've tried so far...) but yes, it's nuts for your car. The fuse marked HS is a shunt, but it's supposed to be fuse 1

I dunno, check them all? There's a few of them look dodgy from here...

Also, look for signs of serious bodgery

[Valandil]

I think its SH, as in SHunt.... I hope that's the cause of my airbag supply voltage fault!

Yea I have a feeling this thing is all over the place. All the fuses themselves are fine, but like I said I really doubt whether they're all in the right places. I'm just nervous about changing them all round and blowing everything up! Especially when the positioning of the slots (not to mention what's actually in each slot) doesn't match the handbook.

I haven't seen any signs of major bodgery, but I'll have another look tomorrow.

Thanks for your help so far!

[Valandil]

I am a very happy man right now!

I didn't realise that there are numbers on the fuse box! They seem to confirm that my fuse box is upside down compared to the handbook. So I went down my local scrappy (who actually had a coupe which I was surprised about) to get the green shunt I was missing, pulled every fuse out the box and repopulated it by the handbook and now everything works!

God knows how long this car has been ambling around with that fuse box all over the place! The only bit that doesn't seem to work is the sunroof isn't automatically closing when you lock the car, which it should do, but the windows work.

Thanks for your input Steve!

[steve_earwig]

Erk I didn't think full mux cars had total closure

Congrats on getting it sorted anyway. In your pic above it looked to me like the fuses couldn't even go in the right positions and I thought you'd have to pull them one by one to see what stopped working

[Valandil]

Yea I did pull a few fuses to see what stopped, matched up to the handbook so it gave me confidence it should work.

Yea the handbook says it has total closure, and like I said the windows work, just not the sunroof