One problem related to defogger has been reported for the 1999 Hyundai Sonata. The most recently reported issues are listed below.
Consumer loss control and hit a solid barrier and none of the airbags deployed. Driver sustained a head injury. Prior to the accident the vehicle was taken to the dealer because the air bag light illuminated. The dealer removed and replaced the passenger seat air bag module. The dealer also performed recall 02v105000 related to the side impact air bag wiring harness routing. The rear defogger button flashed intermittently and the a/c and defogger were inoperative. The dealer replaced the control head. The outside rearview mirrors would not move right or left. Dealer found break in wiring in right kick panel. The check engine light illuminated. The dealer replaced the canister purge valve. * ph.