S1 Xantia V6 - no start, no central locking

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CitroJim
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

As you say Mike, it'll take luck! And Simon, be careful with the numbers as they can rub off easily. One good thing is you're looking for a heavy wire and the numbers seem a bit more robust on those...

Fingers crossed...
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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

CitroJim wrote:The Interconnect is a bloody great plug and socket on the firewall on the driver's side just below the scuttle panel.. It is indeed referred to as IC-01 on the diagrams Simon.

It's virtually inaccessible but if you look under the driver's side wing right up in the top and above the mudshield and relay box then you'll see the loom disappear into the interconnect on the firewall..
Hi Jim,

I was afraid of that! This just keeps getting better and better... #-o :lol:

I have been doing some testing on the fuse box today to work out exactly what on the drivers fuse box is powered via the faulty wire coming from the 40A Maxi Fuse D in the engine bay... and its a lot:

Directly powered from Maxi Fuse D not via the shunt:

F1 (10A) - Radio main supply, but only if the fuse is in the radio without key position. (Which I don't use)
F7 (20A) - Horn and Towbar. (No towbar fitted)

Powered from Maxi Fuse D via the shunt:

F14 (5A) - Coolant temperature warning, injection ECU permanent live (memory)
F15 (10A) - Diagnostic socket, alarm relay, interior/boot lights, anti-theft permanent live.
F25 (2A) - Radio memory, clock, PLIP (IR receiver) electric (heated ?) seat relay, alarm LED
F27 (30A) - Electric Front windows.

Now we know why the engine wouldn't start - both the engine ECU and immobiliser keypad permanent lives come from this feed. #-o So even though they both had ignition switched power they were missing their permanent lives.

So after studying the problem I have the following options, roughly from worst to best in terms of bodginess....

1) Solder a wire from the right hand side of Fuse 17 to the middle of the shunt. The right hand side of F17 is a separate permanent live that comes from Maxi Fuse C (80A) in the engine fuse box, in fact it's the only other permanent live present on the drivers fuse box from which to take an alternative feed. It's intended purpose is to supply the alarm, and F17 is the only fuse on the drivers fuse box that uses this feed from Maxi Fuse C.

I know this will work at a pinch because I already connected a crocodile lead this way and was able to start the car and everything including radio, clock, front windows etc seemed to work. But its far from ideal because there are some heavy current users supplied by the shunt - front electric windows in particular. And on the rear of the fuse box the feed for the shunt is a big meaty terminal whereas the other permanent live for F17 is one of the small terminals, so whilst it might work in the short term I'm concerned about the small terminal on the rear overheating. F17 is 15 amps so this was the absolute maximum ever expected of this small terminal.

2) A significantly better option would be to tap into the permanent live going to the ignition switch, on one of the three double pin plugs under the steering wheel assembly where you would do the ignition switch relay modification. This comes from maxi fuse A - I haven't actually checked to see how many amps that fuse is yet (anyone know off hand ?) but I suspect its either a 40A or 80A, so should be able to take the additional load which is only going to be heavy when the front window winders are used.

I can then either splice it into the thick cable that comes into the back of the fuse box from the broken wire, or solder it directly to the bridge on the front of the shunt, which will supply both the pre-shunt and post-shunt fuses. As much as its a little bit ugly to have a wire soldered there, I think the obvious choice is to solder it to the shunt - because trying to splice that heavy wire up above the back of the fuse box and jam that all back in there without something shorting together would be very difficult indeed. It's just far too cramped with too many plugs and too many short and stiff cables. And then if I ever wanted to repair the wire under the radiator properly I'd have to take the fuse box out again and remove the splice - also very awkward and messy. Whereas with the shunt approach I could just unsolder the wire off the shunt and disconnect it at the ignition key end in a few minutes with little fuss.

So provided that maxi fuse A is sufficiently large I think I'm going to take option 2. If it's only a 20A one I could probably swap it with maxi fuse D which is 40A, and won't be doing much work due to the broken wire.

3) If I can get access to the wiring in the wheel arch I could potentially link together the wires coming from maxi fuse C & D, thus achieving the same result as option 1, but without passing all the current via the small terminal at the back of the fuse box. It would still be fed by maxi fuse C but via the large terminal.

4) Run a new wire right around the engine bay and try to splice in near the interconnect - but if the interconnect can only be reached under the wheel arch liner that then leaves the job of trying to get out of the wheel arch back into the engine bay to go to the engine bay fuse box....

What do you think about plan 2 Jim ?
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

Plan 2 is about the best Simon and it's not hard to implement... That's a pretty hefty feed as it has to run the blower...

As long as you don't run the blower at full-tilt and the heated rear window at the same time you should be OK...

I'd do that and then perhaps when feeling keen about it try to redo the duff splice properly...

At least option 2 is a pretty quick one and not too painful..
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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

CitroJim wrote:Plan 2 is about the best Simon and it's not hard to implement... That's a pretty hefty feed as it has to run the blower...

As long as you don't run the blower at full-tilt and the heated rear window at the same time you should be OK...

I'd do that and then perhaps when feeling keen about it try to redo the duff splice properly...

At least option 2 is a pretty quick one and not too painful..
Yes I agree. I checked an old photo from my Series 2 and Maxi Fuse A is 60 amps there, so if the Series 1 fuse is also 60 amps I think I should be OK. Will check when I get home tonight.

Apart from when I'm using the front window winders there should only be a few extra amps going through the 60 amp fuse than normal, and the cable is quite heavy gauge.

They do seem to rely on not everything drawing maximum current at once because I notice that Maxi fuse D is only 40A, yet if you sum up all the fuses that are supplied by it you get 77A !!

Worst case scenario is the maxi fuse blows if all the high current drain devices are in use at once, but at least I won't be melting the terminal in the back of the fuse box...

BTW where do you get those big maxi fuses from ? I haven't seen them for sale before...
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

Might be best to carry a couple of spare Maxi fuses with you Simon... If you have none I have a few knocking about...
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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

I have no spare maxi fuses Jim. Let me check how many amps fuse A (that feeds the ignition key) is - if it is a 60A as I suspect, I wonder if the solution to my issue is to simply "upgrade" fuse A to an 80A ? That should give enough extra headroom to power the shunt related fuses that would normally be powered by fuse D, but not be such a big increase as to risk damage in the case of a short.

With the shunt being powered from the permanent live to the ignition switch as described in option 2 above, and the maxi fuse being upgraded from 60 to 80A it should hold together as a permanent repair, as to be honest I don't know if I would ever get around to taking the front bumpers off to chase the broken wire when I have too much other work to be doing around the property...
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

Yes, that's a good thought to uprate the fuse Simon, technically you have a spare but if I have an 90A one here spare and you want one, PM me your address and I’ll pop one in the post next week..
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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

Thanks Jim, I might follow up on that offer if you have an 80A spare. :)

I don't actually have a usable spare left over - The original Fuse D is 40 amps which is not enough to run both ignition and shunt circuits, also It's possible that Fuse D goes other places than just the shunt in the drivers fuse box, without studying all the different circuits (including ones I don't have) I couldn't tell for sure, so I need to leave the original fuse in place just in case it had other destinations that were before the break in the wire.

I think all the maxi fuses go to multiple destinations.
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

Simon, I'll check my stock...
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Re: S1 Xantia V6 - no start, no central locking

Post by Stickyfinger »

I do if Jim does not.....I can give it to Jim at the weekend or post it up
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Re: S1 Xantia V6 - no start, no central locking

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Stickyfinger wrote:I do if Jim does not.....I can give it to Jim at the weekend or post it up
Sorted! Thanks Alasdair :D
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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

Hi Chaps,

Thanks for the offer of a fuse, it's greatly appreciated :) I've confirmed that the original Maxi Fuse A which provides the main ignition switch feed that I will be tapping into is 60 amps, seen in black on the right:

Image

So to uprate it a bit for the extra work it will be performing its an 80A fuse that I will need, which is normally used in slot C. So if you have a spare 80A fuse that would be brilliant.

Despite what I said about soldering to the front of the shunt I changed my mind and decided to do a neater job by doing a soldered splice into the wire going into the top of the fuse box so that there is no visible modification:

Image

Although the wires are short there is a bit more room in there than I first thought so I think this will make a nice neat permanent repair. I've done this end of the link but I'm yet to finish the other end thanks to once again being rained on part way through the job. [-X

BTW Jim it turns out the feed to the ignition switch I will be tapping into is not the same feed that runs the climate control blower, that is a separate feed. In the picture below the black plug is the one I will be using which is the main switched ignition feed in and out, while the brown plug is the feed for the climate control and blower, which I think is dedicated to that job, and runs off the 40A Maxi fuse B. (Citroen have kindly colour coded the fuses to match the connectors!)

Image

You probably noticed some wiring that shouldn't be there including a buzzer and an inline fuse - that's part of the "bomb detector" connected to both the permanent live and switched live on the black plug, :lol: I have half a mind to cut it out because it causes me nothing but annoyance with its beeping and false alarms every time I open a door... :twisted:

I don't know where the main controller for it is located but there are literally cables running all over the car under the carpets, behind the dashboard etc... :x
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Re: S1 Xantia V6 - no start, no central locking

Post by RichardW »

Might as well do the relay blower mod while you are there, saves having to remove the steering wheel again!!
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Re: S1 Xantia V6 - no start, no central locking

Post by Mandrake »

RichardW wrote:Might as well do the relay blower mod while you are there, saves having to remove the steering wheel again!!
Actually it's not necessary to remove the steering wheel to get access to these three connectors and do the relay mod - the steering wheel is still very much in place in the photo above! :-D

I do actually have a suitable relay and terminals, somewhere.... I don't have any heavy enough wire for 40A though so will need to get some. I'll leave it until the weather picks up a bit I think, with the car off the road now since Monday the other half is chomping at the bit to have it back on the road again so any extra work attempted in the rain keeping it off the road even longer would be frowned upon. :twisted:

It's only a few screws to get the panel off to get access so its no problem to do it later.
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Re: S1 Xantia V6 - no start, no central locking

Post by CitroJim »

Simon, that looks a good neat job for a quick work-around and some very useful knowledge has come out of this thread which is excellent and sure to be of great value in the future...

I too would recommend you do the blower relay mod... It'll be needed sooner or later ;)