My brothers 1998 S70 runs well, but lately when he accelerates the battery light flashes on for a few seconds, then it goes off.
Any ideas? Thanks, Peter

The belt could be getting old and in need of replacement. The battery is showing it's age. The alternator brushes are loosing their grip and need replacement.
Check all of the above. Try turning the AC off and accelerating, if it still glows read, then I would suspect that the belt is OK.

Klaus
--
(V♂LV♂s 1995 854T, 1998 V70R)

Probably some corrosion on the battery terminal or a loose ground. Check all of your connections. It's probably not a big issue now, but could become one if you let it go...either this or battery losing it's stuff if over 5 years old, especially.
--
1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.