Problem

• Chevrolet technical service bulletins (TSBs) indicate that the Astro suffers from "lack of heat," particularly on the driver's side. TSBs report that the lack of heat primarily occurs at the front defrost/defogger vent location.
  
  

Consequences

• Although defroster failure may result in minimal spots on the windshield, it could become a serious problem. A defroster lacking heat may cause poor visibility, which might lead to an accident. If the defroster stops functioning altogether, it is recommended you not drive in inclement weather.
  
  

Solution

• Prior to addressing a heating problem, examine the defogger vent to make sure an obstruction is not restricting heat flow. If airflow restriction is not a problem, then a faulty heater core is likely causing the lack of heat.