battery charge fault light won't go out

[david673]

Hi,

I originaly posted this on Monday under a current discussion, but have been advised to start a new thread with it.

Just had a nightmare of a trip to the West Midlands with my 406 hdi X reg. Prior to leaving on Friday i fitted a new battery.
On Saturday evening in heavy snow with the temp at -4 the battery charge fault kept flashing on and off. When ever it did the interior fan would cut out. After 10 mins a burning smell then smoke from under the bonnet. Managed to limp to a relatives to find smoke coming out of the alternator.
Sunday morning with the temp at -9, managed to purchase a new alternator and get it fitted, car started fine and no smoke or burning. However the "battery charge fault" was still lit, and the interior fan and rear windscreen heater wouldn't work!
Drove to my mums in Warwickshire and checked the blower fuses all intact.
This morning the temp was -12 and dreading the drive back to Dorset in such temperatures looked at the fuses again, found one. which stated it was a"battery fault" 5 amp fuse. I pulled this out and the blower and rear heater sprung in to life! The warning light also went out. However now the windscreen wipers and central locking didn't work!!! So with the engine running i put the 5 amp fuse back in and everything worked. However as soon as i stop the engine and switch back on the dreaded "battery charge fault" illuminates and no blower and no rear heater. So i have to pull the fuse then put it back in again.
Does anyone have any ideas, or am i going to have to perform this ritual for the rest of my 406 ownership?

I've tried resetting the Bsi, but still no joy

David

[steve_earwig]

Very strange Where was this "battery fault" fuse?

[ianjoh]

There is a wire (pink) that goes from the alternator directly to the bsi to indicate if it is working, if the bsi does not get the right signal it will flag a fault and disable the non essential high current outputs to the fan etc (even at -9!). I would think that pulling the fuse just fools the bsi until it is reset.
I would concentrate on checking this wire has a good connection and even go as far as stripping back some of the loom to look for signs of corrosion, it does also go through the multi-pole connector and change colour to yellow along the way.
I am not sure what its normal voltage state should be but I will have a look at mine this w/e (if allowed).

[steve_earwig]

That's interesting. I was wondering if there was a short circuit elsewhere but now I'm thinking either the old alternator buggered something up when it went or the new one's come with a fault

[david673]

Guys thanks for the advice, i've got to work the next 2 days so will have a look on Boxing day, and will also update you with the fuse number that makes the warning go away. merry xmas, david

[david673]

I've solved this by pulling out the 'engine running signal relay' in the fuse box under the bonnet. Every electrical item now works and i don't get any warnings re 'battery charge fault'. However the warning system still works as i occasionaly get the dreaded 'low brake fluid' warning light when i apply the handbrake. David