Two problems related to ignition switch have been reported for the 1998 Volvo V70. The most recently reported issues are listed below.
The ignition switch frequently jams, locked, in the "off" position. The key can be inserted, but the ignition lock will not turn, making it impossible to start and operate the vehicle or turn on accessories or turn the steering wheel, rendering the vehicle completely inoperative. When the ignition is in the "on" position, it can be turned off without difficulty. When it is "off," however, it frequently can not be turned "on". A quick internet search revealed that this is a rather common problem.
Ignition switch failed. Nlm.