mine is a s70 '98 gle, i tried that thing with the swich and the trip reset button, its not working. the light is not flashing even after 30-40 sec. and its stil on.
is there anything else i can do? (if needed, an universal obd can be arranged).

 

I think I read something like 98' needs some reset tool and that thing you tried works for 99+ models. I may be wrong, but I think I read in the thread in this forum.

 

You need a special Volvo reset service tool. If it bothers you to much remove the bulb.