Very strange car fault - Citroen C2 - fuse box? BSI? BSM? Please help

[agi1190]

Checking the wiring diagram would possibly help with the puzzle... I guess?

 

[Ziggie]

So let’s place bets:

my bet goes that it is a wonky earth connector near the battery / fuse box where the connection is rusted or loose . This includes the battery clamp.

long shot!

 

[agi1190]

The whole fuse box was replaced recently, which only "worked" for a couple of days. I'll let you guys know once (if) I get my car started and bring it to the mechanic. I'll have a longer chat with the guy once I'm there and see if he has any ideas.

 

[Mike Johnson]

If as you say the mechanic replaced the fuse box he must have disconnected the battery, to me this all seems to point to a battery fault, connection, negative or positive or internal to the battery itself.

 

[DPG]

If as you say the mechanic replaced the fuse box he must have disconnected the battery, to me this all seems to point to a battery fault, connection, negative or positive or internal to the battery itself.

You would hope the garage would already have eliminated this as a matter of course, but you never know.

 

[agi1190]

Battery seems to be working fine, there are no issues with starting, when the car is not faulty, and both mechanics I went to with the problem, as well as the AA recovery guy, said that the battery is fine and there is no evident problem with that. I've had a few attempts of resetting, disconnecting and reconnecting various things, with no result (even found a method for resetting BSI module, but no success). While I aim for a miracle to happen, with little idea what I'm doing, nothing helped so far.

 

[static zap]

Do you have any blinking security active light at rest , to compare two conditions (good.bad) ?
When dark enough to see !

 

[Ziggie]

Checking the wiring diagram would possibly help with the puzzle... I guess?

The whole fuse box was replaced recently, which only "worked" for a couple of days. I'll let you guys know once (if) I get my car started and bring it to the mechanic. I'll have a longer chat with the guy once I'm there and see if he has any ideas.

Good luck . Let’s know the answer!

 

[ruston]

As @Ziggie . A bad earth could cause those problems too, but as @DPG you would think this would have been checked by the qualified people that have already examined it .
However ensure the negative battery connection is sound and connect a jump lead between that and a good connection to the engine block to see if that eradicates some of the symptoms.

 

[DPG]

As @Ziggie . A bad earth could cause those problems too, but @DPG you would think this would have been checked by the qualified people that have already examined it .
However ensure the negative battery connection is sound and connect a jump lead between that and a good connection to the engine block to see if that eradicates some of the symptoms.

I agree, if they haven't checked battery, grounding, fusebox supply etc then you need to take it somewhere else. This needs someone who is experienced in diagnostics.

The earthing lead suggestion above is worth trying though, and nice and easy to do.

 

[static zap]

My first step would be with a cheap voltmeter ,to check nothing strange going on with battery volts and a lightly used car.
..can also look for volts on things earthed -allegedly- ..

 

[ruston]

Have you checked the MOT history to see what any past failures were. Has it it suffered any collision damage or advisories on corrosion observations. Some failures may give you a clue to a progressive fault.

 

[stanwelbach]

Could be a number of things which I will expand on later but first can I ask that when the car is faulty, do the headlights work at full brightness? If so this rules out a bad battery and parasitic draw (as the battery would go flat on a regular basis)
Is the starter motor and its circuit in working order(has this been confirmed by the auto electrician)?
Please report back for part 2.
.

 

[agi1190]

The car decided to start today after 3 days(!), took it straight to the mechanic. Told him some of your ideas guys, it might take days to get it sorted though. I will keep you updated.
After turning the car off, the fault came back on soon as it was locked, so mechanic saw it as well. We'll see, fingers crossed. Soon as this is sorted I'm probably going to sell it as I honestly can't trust this machine anymore.

 

[agi1190]

Could be a number of things which I will expand on later but first can I ask that when the car is faulty, do the headlights work at full brightness? If so this rules out a bad battery and parasitic draw (as the battery would go flat on a regular basis)
Is the starter motor and its circuit in working order(has this been confirmed by the auto electrician)?
Please report back for part 2.
.

When the car is faulty, there are no lights whatsoever, it's not a battery or alternator, had that checked already.