Home >> Lincoln >> 2006 >> Navigator 4WD >> Repair and Diagnosis (Single Page) >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> HVAC Climate Control System-General Information And Diagnostics >> Diagnosis And Testing >> Climate Control System >> Pinpoint Tests >> Pinpoint Test X: The Temperature Control Is Inoperative Using The Front Auxilliary Climate Controls >> Possible causes