Vectra 2.0 Automatic - Battery Light

Battery light came on this morning and stayed on after ignition. No problems with the drive to work (18 miles), but I noticed that when I the engine was idling (a bit high at 1,000rpm), the light was bright. As I moved off and the engine revs got higher the light gets dimmer, I popped the gear into neutral and revved the engine, expecting the light to brighten, but it's the opposite, it goes dimmer.

So when I get to work, tunr off the engine and try to re-start - dead battery (as expected).

I'll pop a new one on to get me home, but I'm guessing the alternator has gone ???

Has anyone else had similar .... the battery light going dimmer the faster the engien revs ????

Reply to
Phil Mac
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No, it's at it's brightest when the alternator is not charging, and will go dimmer and then out as it charges. You usually only see it on or off.

Yep.

Probably the alternator is a bit weak (worn brushes perhaps?) and *just* manages a bit of charge at higher revs- just enough to turn the light out.

Reply to
Chris Bartram

many thanks. Just popped a new battery on and it's the same, Light stays on, but goes much dimmer as I rev the engine.

HHmmmmmm. There's a perised breather hose at the top of the engine, connecting cam cover to air intake, which may throw a bit of oil. Could that have chucked crap onto the brushes ?

Is it possible to clean the brushes ?

Reply to
Phil Mac

Re crap on brushes - I'm sure thats poss. A friend of mine has limos for hire and he was having alternator problems (which is a big prob. on a 28ft stretch auto. limo at night with all lights/dvd/stereo etc with paying guests on board!) and that turned out to be a tiny water leak when hot which was spraying little jet of water into alternator. You couldnt see it when cold on yard morning after - was a bugger to find!

Reply to
Matthew Millichap

However by the time you've got to the brushes you might as well change them.

Reply to
Duncan Wood

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