battery light glowing at high rev's 348.

[pneumothorax]

any thoughts? coming home last night and when hitting moderately high revs the light started coming on. now i havent used the car for a week or two but it had started fine, has recent new battery and refurb'd alternator. apart from having the lights on no other drain on battery. and it starts fine this morning. i would have thought that at high engine speeds the battery would be charging rather than feeling drained..or am i looking at an electrical gremlin? thanks for any advice.

[burriana]

Well, if it's not the alternator, then probably a lose earth or other connection.

Either way, those lights don't usually come on for no reason so I'd get it checked rather than forget about it ... (until it reminds you late at night in the middle of nowhere that is!).

[Lars87]

Belt slipping at high revs?

[here]

On one of my cars i have always had my light some times flash on and of. Even after replacing the alternator last year which was rebuilt with uprated parts. It still does it. Its some loose wire or something but i cant find it, i have even looked behind the dash. All the earth leads are new and tight and even plugged to the SD2 it cant be located. Its all charging correctly, it just flickers on and of especially at high revs.
Now i just live with it, i have even drove to Lemans, nurburg, Spain and Italy last year. Its baffling, its Ferrari

[burriana]

burriana said:

those lights don't usually come on for no reason

Ok, so forget I said that

[pneumothorax]

thanks all. sounds like it might be a "they all can do that sir" issue then. i've spoken to qv and i suspect its got something do with the fact i electrocuted my 348 a while back..

[burriana]

pneumothorax said:

thanks all. sounds like it might be a "they all can do that sir" issue then.

In all seriousness, I don't think it is. My two have never done it and I would be very worried if they did and want to find the cause. I do too many long trips to risk something letting me down that I knew about.

These are also the first cases i have heard of, but that is not to say they are uncommon.

Best asking on Ferrarichat to be honest. They are the technical gurus.

[here]

Although some of the tecnical gurus are also now on www.Ferrarilife.com as well;)

[bob-in-toon]

I had exactly the same problem on my 348 and it turned out the alternator had gone.

[FezzaDezza]

Sounds like the voltage regulator, stick a multimeter on it with the engine running and give it a rev. If the voltage remains reasonably constant at around 12-14V then all is fine. If you start seeing 14V upwards climbing even higher as you rev then its most likely the regulator. Easy job to do in a couple of hours and parts are peanuts, better to change the rectifier at the same time also since you'll have the alternator in bits anyway.

If the voltage is <12V then that could again be the regulator or something more serious within the Alternator. I went through 3 or 4 voltage regulators which kept blowing before getting a specialist look at the alternator. Turned out I had a hairline crack in the casing and an intermittent fault in one of the windings. They managed to match up the part numbers to find an identical one in stock (Denso alternator fits something daft like a landrover also) which they sold me for about £100. Fitted it 2 years ago and never had a problem since!

You might also want to fit a beefier earth strap from the alternator to the chasis whilst your at it as the stock earth is pretty pants and can cause problems. I got some earthing straps off ebay for a few quid.