406 BATTERY CHARGE FAULT

[womble171]

Hi guys....

I have a 2000 406 110hdi and when I first start car in the morning the blowers work intermittently and shows up battery charge fault on the LCD. After a couple of mins running this seems to clear up, seems to take longer to rectify itself the colder the weather is??? Would I be looking at the alternator, or battery at fault...

[Doggy]

You need to measure the battery voltage with the engine running, preferably while it's misbehaving.

Should see 14.0 -14.5 V. across the battery, (maybe a little less briefly after a cold start).
If it's significantly lower / varying, you next need to measure the alternator output voltage.....
If that's the same and the drive belt isn't slipping you have an alternator problem.
If it's OK, you have a battery cable / connection / earthing problem.

[womble171]

Thanks mate.

Hiw do I test the alternator output voltage? The drive belt ain't slipping, unless it can slip and not squel??

[Doggy]

With the engine stopped, measure from the alternator casing to the big output terminal *, (you should get the same voltage as across the battery).

Then very carefully repeat with the engine running, avoiding all the moving bits.

* this is definitely accessible on mine as I proved it with a pair of pipe grips on Saturday, while undoing the oil filter.