not starting - isn't turning over but some of the electrics work

Hi, I'm new to this forum. My 2003 mk1 C3 isn't turning over but some of the electrics work. I was trying to wire in something and saw the shunt fuse spark. Since then this is happening. When I put the ignition on, the sidelights are on even though they are switched off. Only the windows, hazard lights and dash lights are working. When I try to start the car it sounds like the bsi or immobiliser is stopping it from starting as the battery is new and there isn't any other issues. Please help.

toyotaahir wrote: ↑Thu Jun 25, 2020 3:49 pm I was trying to wire in something and saw the shunt fuse spark.

Hi

Disconnect your wiring modifications first.

Replace the park shunt with a 40A fuse.

See if you can start the car.

Hi, thanks I tried this however the standard 40A fuse doesn't fit, also unplugging the wire I tried to fit didn't do anything. Surely if the shunt fuse is faulty there would be no electrics working?

toyotaahir wrote: ↑Thu Jun 25, 2020 4:39 pm Surely if the shunt fuse is faulty there would be no electrics working?

No. You don't understand what it does and what it is for. Maybe this is the reason you managed to get sparks where there shouldn't be any.


If you can't make a fuse fit the park shunt, you need to source a replacement part that does fit.

Only then will you know if you have or have not damaged the BSI. You may well have just made the car uneconomical to repair.

toyotaahir wrote: ↑Thu Jun 25, 2020 3:49 pm My 2003 mk1 C3 isn't turning over but some of the electrics work.

On the surface it looks like you have toasted the BSI.

You have written that the engine "isn't turning over". Do you mean the engine wont run or the starter motor doesn't run? If the starter is not running that has nothing to do with the BSI so I assume you mean the engine will not run.

With the park shunt removed most of the electrics wont work. However the dash will light and the starter will engage but the engine will not run. So it looks like the shunt is still serviceable but that's not good news.

Do you have the credit card sized engine pin code card? It's a grey card with Citroen and a key marked on it.

There are a number of options for replacing the BSI but they are either expensive or convoluted.

Yes it's the engine that isn't working. Starter motor can be heard when turning the key.
No I don't have any codes as I'm the 5th owner of the car unfortunately.
I will try the bsi reset procedure and check if all the fuses are ok, I think it may not be worth changing the bsi as I've heard of others who have done that and still had the same problem (unless of course they went to the dealer).

SOLVED:
Fuse 4 & Fuse 22 were out, put in 2 new fuses and it fired into life. So it wasn't BSI failure.

Side lights working properly?

Yes everything's working as normal