Three problems related to defogger heater have been reported for the 1997 Jeep Wrangler. The most recently reported issues are listed below.
Unable to defrost windows, no air flow from vents due to internal lever in heater housing broken, vehicle unsafe to drive in cold weather.
When turning defroster on, there would be a popping sound. Have taken vehicle to dealer & mechanic said lever had separated that caused defroster not to work. It needed replacing. This was done at least 6 different times.
There is a malfunction in the heater core that causes windows to fog up when engine is heated. Dealer has not seen vehicle.