battery warning light

My newly bought 240 GL estate had a completely flat battery.When I charged it the battery warning light came on after a few seconds without the engine being started. Assuming the battery was a goner(I noticed a couple of dry cells)I bought a new one. Unfortunately the battery warning light still comes on but only when the engine is switched off. I'm guessing a short somewhere in the warning light circuit but don't know where to look. To save battery drain I am removing one of the terminal connections but if anyone can tell me at least which wire is the right one I can remove it until the next service. Thanks
levenax

http://pic7.picturetrail.com/VOL188/...8/23744414.jpg

If you disconnect the warning light wire the alternator will not charge at all. The light provides the exitation current that starts the alternator charging.

If you look at the alternator it should have 3 wires on it,a thick wire probably red (the main battery wire), a thin wire (again may be red) this is the warning light wire, and an earth wire from the frame of the alternator to the block.

Check the earth wire to the block for good connections/breaks.
If this is OK remove the warning light wire and switch the ignition on, the light should be off. If the light is off, earth this wire and the light should illuminate.

If this works OK your problem is in the alternator, not the wiring.
You don`t say what year your car is but pre `86/7 Volvo fitted the dreaded bio-degradeable wiring harness which sheds it`s insulation, especially in areas where it gets hot, as it does near the exhaust, if the light stays on when the wire is disconnected it could well be caused by a short in the wiring.
Good luck,
Colin.

Gee, that's a real sod Colin. Any chance of assassinating the designer? I'll check out your very helpful advice.
Many thanks for your reply.
Brian

Did the checks suggested and found that it was indeed the alternator.Bought a second hand one from a breaker and all seems well. Thanks.
Brian