Battery warning light over 3100rpm ?!?

[bucky]

The beast has started with a strange problem today.
The Battery warning light comes on at exactly 3100 rpm and stays on throughout the whole range above that.
When the revs drop below 3100 it goes out.

The VCT seems to be working fine as i get up to 4000.

The light comes straight on not even fading in and out as if the battery was losing change,

Anyone had the same problem or have any clue asto how to fix it??

 

[martinthrapston]

alternator is knackered or auxilary belt is slipping

 

[warrenpenalver]

You need to put a multimeter to check the voltage on the battery and rev it from the throttle body while you do.

 

[bucky]

Cheers guys, will be checking it over this afternoon.

 

[Anonymous]

my battery light has been doing this for a while lol...

keeps coming on and off, flashing etc... I put some cleaner through the alternator and seems to stop it for a while...
gonna take it apart and check the internals as cant really afford to get a new one..

 

[Dal]

When it does it, does it go out again if you put a high load on with the air con or front heated screen?

Mine's done that for the last 3 years. I haven't noticed it since I changed my Coil and HT leads last month. Might be coincidence though.

 

[bucky]

I turned everything on, full beam radio on full tilt till me ears were bleading, anything that was elecrical went on, still wouldn't light up till 3100 rpm and stayed on until i bounced of the rev limiter.

I think it just needs a good slap.

 

[martinthrapston]

cars time of the month mate lol

 

[bucky]

Got myself a couple of hours down the workshop this weekend, time to play around and do some diagnostics.

might even have a look at giving beasty a service.

 

[hotrodspike]

Diode pack in the alternator's rubber ducked mate.

 

[bucky]

The Beast now has a shiny new Alternator ........and problem solved, new Aux belt at the same time, a messy Saturday at the garage and a quick service, running like a dream now !!