Help please, 1997 Vauxhall Astra - battery light won't go out

[P3ter]

I'm having a problem with the above car. I've done a few basic checks, listed below, and still don't know what to do. Any suggestions/help would be greatly appreciated.

My 1st thought was that it could be the fan belt but that's ok.
Also noticed the light stays on even when the ignition key is removed - I've never seen that before.
Tested the alternator output by putting multimeter over the battery terminals while engine is running, reading was 13.3V at idle and 14.5V at about 2500 rpm
That makes me think the alternator is charging the battery ok.
Next I tried to test for current drain off the battery. Removed battery lead, connected multimeter between lead and battery, got no reading. Tried same test with tester with bulb, bulb didn't light up.
Battery light was still on with ignition off so I tried taking out & replacing each fuse one by one to see if I can find out which circuit the fault is on. Light never went out when I removed any of the fuses but it did flicker slightly when I removed or replaced fuse number 7 which the handbook lists as being for display/clock, fuel guage & dashboard lights.
Also noticed when engine is running, the battery light gets brighter when I rev the engine.
One final note: I used to fit car steroes for a living (although I wouldn't say I was great at it) and have seen problems with the dash lights on vauxhalls about this age when a stereo has been fitted wrongly (switched and permananet live not swapped) so i took out the stereo to see if there was a problem there (It is the original stereo but some screws were missing and there was a little bit of damage in behind it so it looks like another one has been in it at some stage). That wiring all seemed ok.

So now I've no idea what the problem could be. Charging seems ok, can't find any current drain. Also the car sat overnight and my wife is off to work in it this morning so it must have started ok.

Any suggestions for what I could check now or how to fix it, please?

Thanks for reading this long post, Peter

[Graham-W]

I would suspect the rectifier pack in the alternator. When you check the output voltage (like you did across the battery) switch your multimeter to AC to see if there is any un-rectified voltage coming through.

[chas2008]

would have said an alternator all day long....especially as the charging light is on when switched off & key removed....

[Iggle Piggle]

Sorry, don't know the answer but get it sorted soon, my old VW Polo did this then caught fire in the office car park next to the MD's new BMW ...

[Iggle Piggle]

and we found it was the alternator after we put the fire out ...