Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

[napping]

Harness side

Thanks - that makes sense. I'll try that tomorrow when storm Arwen eases

[ozvtr]

Earlier I removed the BSM to inspect the maxi fuses and tested each fuse to see if any were blown - none were. So far I haven't pulled any of the maxi fuses out as they felt well seated and they didn't want to budge. Perhaps the next step is to test for an open circuit to the BSI - but without a wiring diagram for the Mk2 I fear prodding with a multimeter could do more harm than good!

I bought a Haynes manual specifically for a wiring diagram, but the manual only shows the Mk1 BSM/BSI - and despite trawling the net I have not managed to track one down yet.

It is VERY rare that a maxi fuse would blow. You would probably see smoke first! I was thinking more along the lines of corrosion on the spade connections. So I would remove them and look for something amiss.
Lack of power to the BSI alone does not explain why the car wont start. If it was just lack of power to the BSI...the engine would still turn over. Nope, you have to go further back. Hence my other ranty posts mulling over the symptoms!

Can you try disconnecting the plug on the yellow connector shown below (the plug iteslf will probably be grey).
Give Pin 2 a 12v feed & see if the starter operates. I think the pins are numbered right to left as you look at it but please check.
PLEASE ENSURE THE GEARBOX IS IN NEUTRAL BEFORE DOING THIS

The Mk1 BSM has a 2 pin black connector with a single mauve wire going back to the starter solenoid. This allows you to do what Wheeler has suggested, power the solenoid and engage the starter. Why did they get rid of it for the MK2? Don't know! It's very handy if the sensodrive "locks out" in ECO mode.



I think the engine will turn over but I'm not sure it will get you any further ahead. It will test if there is a good connection at the battery, the engine earth and the starter. And it will check the status of the battery (if it turns over the battery is OK). But you said you checked all those things? It wont solve the problem of lack of power to the rest of the car.

Power is getting to the BSM fuses but ON THE SURFACE it appears it is not getting from the battery to the maxi fuses. At this point I'm lost! How can it NOT get from the stud to the maxi fuse block? OR if something in the car is powering up, How is the power getting to some circuits and not others!!?? You have no proof that anything in the car is powering up, except this phantom "beep"!? Ooooh this is frustrating me!

My next suggestion is remove the BSM and the maxi fuse block. Clip the maxi fuse block back onto the BSM and connect the positive battery lead and the nut (if that hasn't already been done). Then check for power at each of the maxi fuses. If you have power there, probe the back of the maxi fuse block where the wires come out to the circuits. If you have power there...I'm done...you have multiple failures throughout your car...but I just don't see it! We are looking for a single point of failure. Your problem has to have something to do with the maxi fuse block if all the other things we discussed (earths, battery etc) are OK.

[wheeler]

Why did they get rid of it for the MK2? Don't know! It's very handy if the sensodrive "locks out" in ECO mode.

Been There , Just a redesign of the BSM, pin 2 of the 5 way yellow works just as good.

I think the engine will turn over but I'm not sure it will get you any further ahead. It will test if there is a good connection at the battery, the engine earth and the starter. And it will check the status of the battery (if it turns over the battery is OK). But you said you checked all those things? It wont solve the problem of lack of power to the rest of the car.

Exactly, this is all im wanting to see at the moment & should confirm nothing has been missed when checking the main earths,power supplies & battery connections. This is very easy to to like not using a good clean connection when using a jump lead as a temporary earth.

Power is getting to the BSM fuses but ON THE SURFACE it appears it is not getting from the battery to the maxi fuses. At this point I'm lost! How can it NOT get from the stud to the maxi fuse block? OR if something in the car is powering up, How is the power getting to some circuits and not others!!??

I did at the beginning of this post specifically ask the OP if there was power getting to both sides of the maxi fuses & they said yes??

[napping]

Been There , Just a redesign of the BSM, pin 2 of the 5 way yellow works just as good.

So, I tried pin 2 on the yellow connector and the engine cranked over like it has a new battery (not surprising considering I replaced the battery back in March).

Next I'll check the leads coming from the maxi fuses, but I guess I'll need to nick the plastic wire coating first in order to test the current on the wires that come from the maxi fuses box.

[napping]

Power is getting to the BSM fuses but ON THE SURFACE it appears it is not getting from the battery to the maxi fuses. At this point I'm lost! How can it NOT get from the stud to the maxi fuse block? OR if something in the car is powering up, How is the power getting to some circuits and not others!!??

I did at the beginning of this post specifically ask the OP if there was power getting to both sides of the maxi fuses & they said yes??

Just double-checked and all the line outputs from the maxi fuse box show 12v+. The engine turns over when 12v is passed through pin 2 on the grey connector. There is a single beep when the battery is reconnected but still nothing else works.

Next I'll see if I can open the deadlocks by passing 12v to it.

On the Mk2 C2 is the connector for this found on the under glovebox fusebox/BSI ?

[myglaren]

Have you tried pulling the maxi fuses and checking the terminals?
They can corrode and although you will get 12V at either end there could be significant resistance - you may even see evidence of overheating on the pins.
A good clean may be needed.

[Hell Razor5543]

Good thought on the fuses (corrosion on the blades). I had the rear wiper on an earlier C5 stop working, and when I unplugged/plugged the fuse in several times the wiper started working again (I had checked the fuse and it looked intact).

[myglaren]

Good thought on the fuses (corrosion on the blades). I had the rear wiper on an earlier C5 stop working, and when I unplugged/plugged the fuse in several times the wiper started working again (I had checked the fuse and it looked intact).

It was your experience with that that prompted my post James.

[Dormouse]

Sitting here on the Subs Bench, I am at a loss too. Oh for a proper wiring diagram!.

One thought I have had is that there needs to be a bus bar which feeds the one input to the several fuses. Could that be the phantom fault rather than all blades being corroded at the same time?

[napping]

Have you tried pulling the maxi fuses and checking the terminals?
They can corrode and although you will get 12V at either end there could be significant resistance - you may even see evidence of overheating on the pins.
A good clean may be needed.

Thanks all for your help with this puzzle!
I checked the voltage on the lines out of the maxi fuses so that it tested the current from the battery, through the live stud, through the maxi fuses and out the other side - all six cables out of the box were live.
It seems like there is a breaker in there somewhere after the maxi fuses. The only clue I get is the beep I get when reconnecting the battery. Not sure where it comes from but it sounds like it comes from the steering wheel area inside the cabin.

[napping]

Have you tried pulling the maxi fuses and checking the terminals?
They can corrode and although you will get 12V at either end there could be significant resistance - you may even see evidence of overheating on the pins.
A good clean may be needed.

That's a thought. Although it's unlikely to be an issue with all the fuses, I might as well try it!

Also, I'll report back with a list of all the engine and glovebox fuses that currently have power or not - to see if that helps a diagnosis!

[ozvtr]

Here is where each of the Maxi fuses power wires go to, you may not have all this equipment and some are irrelevant.
I do not know the colours of the power wires but the ground wires are listed (if applicable). Don't bother with the ground wires at this point.
Its possible the fuse numbers have been swapped around for the MK2 C2 but that wont make much difference, power will still go to those devices.

MF1 - Radiator fan. If you have aircon it's the large connector at the fan. If no aircon, the relay located above the ABS module. Green/yellow wire is ground. Not really relevant.
MF2 - ABS/ESP connector. Not really relevant.
MF3 - ABS/ESP connector. Not really relevant.
MF4 - BSI Large grey 2 pin connector.
MF5 - BSI Large grey 2 pin connector.
MF6 - Heated seats (not relevant).
MF7 - Ignition switch. Green connector at the steering column (see previous post).
MF8 - Power steering. The ECU and connector are are the back of the battery box. Green/yellow wire is ground. Not really relevant.

IF you have power at the back of the maxi fuse block then you SHOULD have power at the above points...if not...good luck finding the problem, you have a broken or corroded wire!
Again I am confused, as from now on I can't see a singe point of failure. Multiple things would have to have gone wrong.

The two points of priority are the green connector at the steering column and the 2 pin grey connector at the BSI.

[Dormouse]

From the Subs Bench again. Is the Immobiliser situated near the steering column and could it beep? Can't see how it would affect all the circuits though but something is beeping so power must be getting that far. Given the number of separate circuits, the fault has to be centralised in the wiring circuit, surely? The chances of several faults occurring simultaneously are so remote. That would point me to a central return earth strap not the feed wires.

Do the side lights work, for instance, or the radio, dashboard, horn or power sockets? What is there that does work?

Does the car have towing electrics, especially S circuit connections, or any aftermarket radios or other associated hifi items?

[napping]

From the Subs Bench again. Is the Immobiliser situated near the steering column and could it beep? Can't see how it would affect all the circuits though but something is beeping so power must be getting that far. Given the number of separate circuits, the fault has to be centralised in the wiring circuit, surely? The chances of several faults occurring simultaneously are so remote. That would point me to a central return earth strap not the feed wires.

Do the side lights work, for instance, or the radio, dashboard, horn or power sockets? What is there that does work?

Does the car have towing electrics, especially S circuit connections, or any aftermarket radios or other associated hifi items?

The beep comes from the steering column area when I reconnect the battery.
No side lights, radio, dashboard, horn, wipers or anything else for that matter.
There are no aftermarket additions, no towbar - everything is as it was when the car left the factory.

If it helps, here is a view of which fuses currently have power (just the fuses, not the equipment);
In the engine fuse box there is power to the following fuses only; 1 - Cooling fan, 3 - Windscreen washers, 12- Windscreen wiper , 14 - Air pump?, 8 - Starter.
On the glovebox fuses, only the rightmost fuses have power, ie. 8, 10, 5, 15, 6, 11.

I'd try tracing the wires from the maxi fuse box but I'm not sure where they go next! Especially MF4, MF5 and MF7

[wheeler]

What is your reg or VIN?
I’ll need to get a wiring diagram up, the question is what diagram do you start with?