Help ,my girlfriend has a 99 Dakota that has not been able to get heat to thecab. although the temp gauge reads 180 on occasion and the motor itself gets warm under hood I replaced the thermostat in hopes of getting her "hot" this hasn't seamed to fix the problem .I am up for suggetions,hoping it isn't the heater core. It is not leaking as of yet. It had the water pump replaced last year. Any ideas on getting her hot again before spring would be much appreciated. David