Two problems related to brake light have been reported for the 1998 Volvo S70. The most recently reported issues are listed below.
There have been repeated failures of light bulbs (turn signal, brake lights, headlights, etc. )-- 12 documented from dealer, another 4-6 not documented because fixed "informally" . The dealer claims the failures are due to cheap halogen bulbs now used by Volvo rather than an electrical system problem. I notice that many of the complaints filed on this make/model involve similar problems. Whether the electrical system or the bulbs are at fault, this is a significant safety problem.
Without warning rear brake lights do not function. Had brake lights replaced. Indicator on dashboard illuminated after service was rendered to vehicle.